EPA-R2-73-261
Environmental Protection Technology Series
JUNE 1973
An Assessment of
Automatic Sewer Flow Samplers
Office of Research and Monitoring
U.S. Environmental Protection Agency
Washington, D.C. 20460
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EPA Review Notice
This report has been reviewed by the Office of Research
and Monitoring, EPA, and approved for publication.
Approval does not signify that the contents necessarily
reflect the views and policies of the Environmental
Protection Agency, nor does mention of trade names or
commercial products constitute endorsement or recommendation
for use.
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ABSTRACT
A brief review of the characteristics of storm and combined
sewer flows is given followed by a general discussion of the
purposes for and requirements of a sampling program. The
desirable characteristics of automatic sampling equipment
are set forth and problem areas are outlined.
A compendium of over 60 models of commercially available
and custom designed automatic samplers is given with de-
scriptions and characterizations of each unit presented
along with an evaluation of its suitability for a storm
and/or combined sewer application.
A review of field experience with automatic sampling equip-
ment is given covering problems encountered and lessons
learned. A technical assessment of the state-of-the-art
in automatic sampler technology is presented, and design
guides for development of a new, improved automatic sampler
for use in storm and combined sewers are given.
This report was submitted in partial fulfillment of Contract
Number 68-03-0155 under the sponsorship of the Office of
Research and Monitoring, Environmental Protection Agency.
iii
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FOREWORD
Although the study was sponsored by the Storm and Combined
Sewer Technology Branch and evaluation comments are made
with such an application in mind, this report is much more
general. It is hoped that it will be of interest and help-
ful to anyone with an automatic liquid sampling requirement,
and that it can serve as a preliminary "shopper's guide".
IV
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CONTENTS
Section Page
I CONCLUSIONS !
II RECOMMENDATIONS • 3
III INTRODUCTION 5
Purpose and Scope 6
General Character of Sewage 6
Flow Modes 7
Variability of Pollutant Concentration. . 10
IV REQUIREMENTS AND PURPOSES OF SAMPLING . . 15
Common Properties and Constituents. ... 15
Type of Sample 17
Adequacy of A Sampling Program 18
Specific Sampling Purposes and
Requirements 22
V DESIRABLE EQUIPMENT CHARACTERISTICS ... 27
Equipment Requirements 27
Desirable Features 29
Problem Areas 30
VI REVIEW OF COMMERCIALLY AVAILABLE
AUTOMATIC SAMPLERS 33
Introduction 33
Descriptive Forms and Evaluations .... 37
VII REVIEW OF CUSTOM DESIGNED SAMPLERS. . . . 153
Introduction 153
Descriptive Forms and Evaluations .... 153
VIII EXPERIENCE WITH COMBINED SEWER SAMPLERS . 193
IX STATE-OF-THE-ART ASSESSMENT 203
Sampler Intake Assessment 203
Gathering Method Assessment 216
Sample Transport Assessment 218
Sample Capacity and Protection
Assessment 222
Controls and Power Assessment 226
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CONTENTS (Cont'd)
Section
X
XI
Numb er
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Page
ACKNOWLEDGEMENTS 229
REFERENCES 231
FIGURES
Page
Runoff Quantity and Quality Data,
Bloody Run Sewer Watershed 20
BIF Sanitrol Flow-Ratio Model 41
Sampler 39
Brailsford Model EV Sampler 44
BVS Model PP-100 Sampler 47
ISCO Model 1391 Sampler 64
Lakeside Trebler Model T-2 Sampler ... 68
N-Con Sentry Model Sampler 88
Phipps and Bird Dipper-Type Sampler ... 95
Protech Model DEL-240S Sampler 110
Quality Control Equipment Company Model
CVE Sampler 113
SERCO Model NW-3 Sampler 119
Sirco Series B/ST-VS Sampler 134
AVCO Inclined Sequential Sampler .... 155
Roarer Automatic Sampler 165
Weston Automatic Sampler 169
NEAR Sewer Sampler 185
Freeman Automatic Sampler Module .... 189
Velocity Contours at Sampling
Station 204
Sediment Distribution at Sampling
Station 206
Region of Validity of Stokes' Law .... 208
vi
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FIGURES (Cont'd)
Numb er
21
22
23
Number
1
2
3
4
Page
Effect of Temperature on Maximum
Particle Size 209
Effect of Sampling Velocity on
Representativeness of Suspended
Solids 211
Effect of Lateral Orientation of
Sample Intake 213
TABLES
Page
Characteristics of Urban Stormwater ... 8
Properties and Constituents of
Sewage ....... 16
Effect of Shape Factor on Hydraulic
Size 220
Ratio of Composite Sample Concentration
to Actual Concentration 225
vii
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INDEX OF COMMERCIALLY AVAILABLE SAMPLERS
Pas
BIF Sanitol Flow-Ratio Model 41 38
Brailsford Model DC-F 41
Brailsford Model EV 43
BVS Model PP-100 46
BVS Model SE-400 50
BVS Model SE-600 53
Chicago "Tru Test" 56
Hydra-Numatic Composite 59
Infilco Automatic 61
ISCO Model 1391 63
Lakeside Trebler Model T-2 67
Markland Model 1301 71
Markland Model 101 74
Markland Model 102 77
Markland Model 104T 80
N-CON Surveyor 83
N-CON Scout 85
N-CON Sentry 87
N-CON Trebler 90
N-CON Sentinel 92
Phipps and Bird Dipper-Type 94
Protech Model CG-125 97
Protech Model CG-125 FP 100
Protech Model CG-150 103
Protech Model CEL-300 106
Protech Model DEL-240S 109
QCEC Model CVE 112
QCEC Model E 116
Serco Model NW-3 118
Serco Model TC-2 122
viii
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INDEX OF COMMERCIALLY AVAILABLE SAMPLERS (Cont'd)
Pai
Sigmamotor Model WA-1 125
Sigmamotor Model WA-3 127
Sigmamotor Model WDPP-2 129
Sigmamotor Model WM-1-24 131
Sirco Series B/ST-VS 133
Sirco Series B/IE-VS 137
Sirco Series B/DP-VS 140
Sirco Model PII-A 143
Sonford Model HG-4 146
TMI Fluid Stream 148
TMI Mark 3B 150
ix
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INDEX OF CUSTOM DESIGNED SAMPLERS
Pa
AVCO Inclined Sequential Sampler 154
Springfield Retention Basin Sampler 158
Milk River Sampler !60
Envirogenics Bulk Sampler 162
Rohrer Automatic Sampler Model I 1°^
Weston Automatic Sampler 168
Pavia-Byrne Automatic Sampler 112
Rex Chainbelt Automatic Sampler 175
Colston Automatic Sampler 178
Rohrer Automatic Sampler Model II 181
NEAR Sewer Sampler 184
Freeman Automatic Sampler 188
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SECTION I
CONCLUSIONS
1. An automatic liquid sampler is one tool of several that
must be employed for the characterization of a flow
stream. Its selection must be based upon consideration
of the overall sampling program to be undertaken, the
characteristics of the flows to be sampled, the physi-
cal characteristics of the sampling sites, and the sam-
ple analyses that are available and desired.
2. In view of the large number of highly variable param-
eters associated with the storm and combined sewer ap-
plication, no single automatic sampler can exist that
is universally applicable with equal efficacy. Some
requirements are conflicting, and a careful series of
trade-off studies is required in order to arrive at a
"best" selection for a particular program. Such a
selection may not be well suited for a different pro-
gram, and a systems approach is required for either th«
selection or design of automatic sampling equipment for
storm and combined sewer application.
3. The proper selection of sampling sites can be as impor-
tant as the selection of sampling methods and equipment.
A clear understanding of the data requirements and ulti-
mate use is necessary as is a familiarity with the sewer
system to be examined.
4. Over 30 prospective manufacturers of automatic liquid
sampling equipment were contacted. Although some omis-
sions undoubtly have been made, it is felt that all
major principles and techniques commercially available
today have been included. These automatic samplers
have been individually described and evaluated for ap-
plication in a storm and/or combined sewer sampling
program. Most of the units surveyed were not designed
for such use, and many manufacturers do not recommend
them for such applications.
5. Although certain commercially available automatic sam-
plers may be suitable for certain storm and/or combined
sewer sampling programs, no single unit appears emi-
nently suitable for such an application. Improvements
in intake design, sample intake and transport velocity,
line sizes, and sample capacity appear warranted.
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A number of custom designed, one-of-a-kind automatic
samplers were reviewed and evaluated for application
in a storm and/or combined sewer sampling program.
Although some of these embodied fairly clever innova-
tions, they were generally tailored around local pecu-
liarities of the application site or program. None was
deemed ideally suited for broad scale use as a storm or
combined sewer sampling unit.
Field experience with automatic sampling equipment was
reviewed with emphasis on recent EPA projects. Leaks
in vacuum operated units; faulty automatic starters;
inlet blockage and line plugging; limited suction lift;
low transport velocities; complicated electrical sys-
tems; and failures of timers, micro-switches, relays
and contacts, and reed switches were among the diffi-
culties frequently encountered.
An assessment of the current state-of-the-art suggests
that the technology is at hand to develop a new im-
proved automatic sampler which will overcome many of
the deficiencies of presently available commercial
units.
One of the greatest problem areas is in the design of a
sampler intake that can gather a representative sample,
even in a stratified flow condition, and at the same
time be relatively invulnerable to clogging or damage
due to solids or debris in the flow stream.
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SECTION II
RECOMMENDATIONS
1. No program to directly compare, in a side-by-side fash-
ion, currently available commercial automatic sampling
equipment has been conducted. It is recommended that
such a comparison be made among some of the more prom-
ising portable commercial units.
2. It is recommended that the feasibility of making im-
provements over the use of standard commercial auto-
matic sampling equipment in storm and combined sewers
be demonstrated by the design, fabrication, and test of
a new automatic sampler.
3. It is recommended that the development of a reliable
flow height gage for use in storm and combined sewers
be investigated. This could be used to provide a sig-
nal for starting the automatic sampler and, given the
hydraulic parameters of the particular sewer in ques-
tion, could be used to provide a flow meter function as
well in certain cases.
4. The greatest deficiency in present day sampling equip-
ment is in the design of the sampling intake. It is
recommended that consideration be given to developing
intakes that will yield more representative samples and
at the same time be relatively invulnerable to clogging
or damage by solids and debris in the flow stream.
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SECTION III
INTRODUCTION
"By a small sample we may judge of the whole."
Cervantes (1605)
Since the very beginnings of primitive man's existence he
has been faced with the necessity to sample, his first
experiences probably being in the area of food and water
selection. The need to sample arises from a data require-
ment that is necessary in order to make some judgmental
decision and presumes the unavailability of the whole. If
the data which are to be derived from the sample are to be
efficacious in terms of the judgmental decision to be made,
however, it is necessary that the sample be truly represent-
ative of the whole, at least in so far as those parameters
which are of interest are concerned. It is this require-
ment, which arises from the nature of the data sought, that
must be the overriding consideration in any sampling effort.
As the civilization of man continued, the exigencies of
social awareness and community led to cooperative sampling
and judgmental decisions affecting others as well as the
sampler himself. In particular, man's requirement for water
to maintain his existence and his concern for the quality of
this water have partially shaped the course of history and
given rise to more formal sampling programs for the common
good. The records of ancient civilizations attest to the
difficulties man has experienced in obtaining an adequate
supply of water, protecting its quality, dealing with sedi-
ment transport in natural water courses, and the like. An
excellent historical review of water sampling, especially as
related to suspended sediment, is given in (1). Suffice it
to note here that despite the fact that the first sampling
for water quality is lost in the antiquity of man's develop-
ment, it was not until the early part of the nineteenth cen-
tury that documentation can be found of the formal sampling
efforts of Gorsse and Subuors in the Rhone River in 1808 and
1809.
From such humble beginnings, reinforced by technology and
man's increased awareness of his environment and his need to
protect it, have arisen even more demanding requirements for
water sampling programs and for equipment to carry them out.
Today a large number of companies have been formed to pro-
duce sampling equipment, and it is to their products that
much of the present report will be directed.
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PURPOSE AND SCOPE
This report is intended to present a current review of the
state-of-the-art and assessment of sampling equipment and
techniques. Particular emphasis has been placed on auto-
matic liquid samplers which are commercially available today
in the American marketplace. These are described and eval-
uated in terms of their suitability for use in storm or com-
bined sewer applications. However, a sampling device which
is suitable for such applications will most likely suffice
for any other municipal waste water application as well. By
collecting and presenting such a review it is hoped that
shortcomings and limitations of these devices for such ap-
plications can be overcome and that this report can serve as
a springboard for the development of new and/or improved de-
vices. In order to assess the probable effectiveness of an
existing device for sampling sewage in storm sewers and/or
combined sewers, or to select criteria for the design of a
new or improved device, consideration of the character of
such sewers and sewage is essential. Questions to be con-
sidered are: What are their general characteristics? What
are the usual flow modes found in such sewers? How do the
pollutant materials carried in the sewers vary with time and
location?
GENERAL CHARACTER OF SEWAGE
Knowledge of the character of the urban environment leads
one to the expectation that stormwater draining from it will
Be of poor quality. Washings from the sidewalks, streets,
alleys, and catch basins are a part of the runoff and in-
clude significant amounts of human and animal refuse. In
industrial areas, chemicals, fertilizers, coal, ores, and
other products are stockpiled exposed to rainfall, so that a
significant quantity of these materials appears in the run-
off. Extreme quantities of organic materials such as leaves
and grass cuttings often appear in storm sewers. In the
fall, such sewers at times become almost completely filled
with leaves. Often during storms large boards, limbs, rock,
and every imaginable kind of debris appear in the sewers,
probably as a result of breaks in the sewers and/or acces-
sory equipment designed to screen out the larger items. One
of the heaviest pollution loads is that of eroded silts and
sediments washed from the land surface. Much of this is
from construction areas where the land has been disturbed
prior to completion of streets and buildings and re-
establishment of plant life. Finally, a significant amount
of solids found in storm runoff originates as dustfall from
air pollution. According to studies made in Chicago (2),
about 3 percent of the total solids load has its source in
dustfall.
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General observation of the polluted nature of storm runoff
from urban areas is supported by a number of studies made in
several large cities in the United States, and in Oxney,
England; Moscow and Leningrad, U.S.S.R., Stockholm, Sweden;
and Pretoria, South Africa. In (2) the American Public
Works Association states, "Stormwater runoff has been found
in many instances to be akin to sanitary sewage in its pol-
lutional characteristics and in a few instances some param-
eters of pollution are even greater". Table 1, which is
taken from (5), contains selected data on the characteris-
tics of urban stormwater.
In some areas, sewers classed as storm sewers are, in fact,
sanitary or industrial waste sewers due to unauthorized and
various other connections made to them. This condition may
become so aggravated that a continuous flow of sanitary sew-
age flows into the receiving stream. Wastes from various
commercial and industrial enterprises are often diverted to
these so-called storm sewers. A rather common pollutant is
the flushings from oil tanks.
Combined sewers are designed and constructed to carry both
stormwater and sanitary sewage and/or industrial wastes.
Therefore, sewage in them has all the pollutional aspects
of storm runoff as described above, but also includes the
pollution load of domestic wastes.
Where industrial wastes are contributed also, a very complex
sewage, with respect to both varied flow rate and pollution
load, is created. The task of sampling and analyzing this
creation with reasonable accuracy becomes an extremely dif-
ficult one.
Because of normal leaks at joints, pipe breaks, loss of man-
hole covers, and other unplanned openings to them, separate
sanitary sewers often carry large flows of storm runoff
and/or infiltrate. This usually occurs in sections of high
ground water level, or where the sewer line is constructed
in, or adjacent to, a stream bed. Under such conditions,
these sewers have much the same character as combined sew-
ers, and require the same types of sampling equipment and
methods.
FLOW MODES
Storm sewers, during periods of no rainfall, often carry a
small but significant flow. This may be flow from ground
water, or "base flow", which gains access to the sewer from
unpaved stream courses. Such base flow may appear as runoff
from parks or from suburban areas where there are open
drains leading to the storm sewer.
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TABLE 1. Characteristics of Urban Stormwater*
Characteristic Range of Values
BOD5 (mg/1) 1->700
COD (mg/1) 5-3,100
TSS (mg/1) 2-11,300
TS (mg/1) 450-14,600
Volatile TS (mg/1) 12-1,600
Settleable solids (ml/1) 0.5-5,400
Organic N (mg/1) 0.1-16
NH N (mg/1) 0.1-2.5
Soluble P04 (mg/1) 0.1-10
Total P04 (mg/1) 0.1-125
Chlorides (mg/1) 2-25,OOO1"
Oils (mg/1) 0-110
Phenols (mg/1) 0-0.2
Lead (mg/1) 0-1.9
Total coliforms (no./lOO ml) 200-146 x 10
Fecal coliforms (no./lOO ml) 55-112 x 106
Fecal streptocci (no./lOO ml) 200-1.2 x 106
* Taken from Reference 5.
With highway deicing.
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Unfortunately, much of the flow in storm sewers during peri-
ods of no rainfall is composed of domestic sewage and/or in-
dustrial wastes. Where municipal ordinances concerning
connections to sewers are not rigidly enforced, it appears
to be reasonably certain that unauthorized connections to
storm sewers will appear. In some cases, the runoff from
septic tanks is carried to them. Connections for the dis-
charge of swimming pools, foundation drains, sump pumps,
cooling water, and pretreated industrial process water to
storm sewers are permitted in many municipalities, and con-
tribute to flow during periods of no rainfall.
Storm runoff is the excess rainfall which runs off the
ground surface after losses resulting from infiltration to
ground water, evaporation, transpiration by vegetation, and
ponding occur. A small portion of the rainfall is held in
depression storage, resulting from small irregularities in
the land surface. The quantity, or rate of flow, of such
runoff varies with intensity, duration, and areal distribu-
tion of rainfall; character of the soil and plant life;
season of the year; size, shape, and slope of drainage
basin, and other factors. Ground seepage loss varies during
the storm, becoming less as the ground absorbs the water.
The period of time since the previous, or antecedent, rain-
fall significantly affects the storm runoff.
In general, storm runoff is intermittent in accordance with
the rainfall pattern for the area. It is also highly vari-
able from storm to storm and during a particular storm.
The design capacity of storm sewers is based on the flow due
to a storm occurring, on the average, once in a selected
number of years (recurrence interval). Usually a recurrence
interval not greater than 10 years is selected for the de-
sign of underground storm sewers. As a result, the design
capacity 'of the sewer is exceeded at comparatively frequent
intervals, resulting in surcharging and flooding of the
overlying surface.
Flow in combined sewers during periods of no rainfall is
called dry-weather flow. This is the flow of sanitary sew-
age and/or industrial wastes, and often includes infiltrated
ground water. As the sewer is designed, dry-weather flow
generally includes only a small portion of the total sewer
capacity, on the order of 10% in the larger sewer sizes.
However, due to overloading in many rapidly developing
areas, the dry-weather flow sometimes requires a much larger
percentage of total capacity. The storm runoff portion of
the flow in combined sewers is as described above for storm
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sewers. However, the design capacity for carrying storm runoff is
probably less than is usually provided for storm sewers.
Sewers for intercepting dry-weather flow from a system of combined
sewers for transport to a point for treatment or disposal have
been designed for enough capacity to include a portion of the
stormwater in the system. In the United States, this interceptor
capacity ranges from two to four times the dry-weather flow. A
weir or other regulating device controls the flow of sewage to
the interceptor by diverting the flow above a pre-selected stage to
an overflow line. The excess flows, or overflows, are carried to
some external channel, such as a creek or river. Thus, raw sewage
is carried to the streams with storm runoff during periods of
rainfall.
VARIABILITY OF POLLUTANT CONCENTRATION
The pollutant concentration in storm and combined sewers is highly
variable, both with respect to the time and with the position in
the sewer cross-section. This is true during periods of no rainfall
as well as during storm runoff periods, but usually to a lesser
extent.
Variability with Time
Probably the most constant character of pollutants occurs in storm
sewers when all flow is base flow derived from ground water. Be-
cause of the slow movement of water through the ground, changes in
concentration of pollutants occur only during relatively long time
periods. Where unauthorized connections of domestic sewage and
industrial waste lines to storm sewers are found, rapid fluctuations
of concentration with time may occur. The domestic sewage consti-
tuent varies with time of day, with season of the year, and probably
over long-term periods. Industrial wastes vary with specific pro-
cesses and industries. Very rapid changes may occur with plant shift
changes and with process dynamics. Conditions on weekends and holi-
days may be very different from those on regular work days.
Observation and experience have demonstrated that the heaviest
concentration of suspended solids during periods of storm runoff
usually occurs during the early part of the storm. At this time,
the stage is rising and accumulated dry-weather solid residue is
being flushed from the sewers,
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and washed and eroded from the tributary land areas. As
runoff recedes, the sewer and land area surfaces exposed to
flow are reduced, the flow velocities which serve to flush
and erode are decreased, and the more easily dislodged sol-
ids have been acted upon. Thus, suspended material is re-
duced in concentration. This pattern of variation may not
be followed during a period of storm runoff which immedi-
ately follows a previous storm runoff period because the
land surface and sewer lines are relatively clean.
Pollutants derived from point sources, such as those from
stockpile drainage, vary at the sampling location with time
of travel from the source to the point of observation. Max-
imum concentration may occur after the peak of storm runoff.
It is conceivable that there would be no contribution from
some point sources during a specific storm because of areal
variation of rainfall in the basin.
The variability of concentration of pollutants in combined
sewer dry-weather flow is similar to that of storm sewers
having unauthorized connections of domestic sewage and/or
industrial waste lines. The fluctuations in domestic sewage
and industrial waste concentration are discussed above.
Variability with Position in the Sewer Cross-Section
Many factors influence the variability of composition with
position in the sewer cross-section. Among them are:
(a) Turbulent flow (as opposed to laminar) which occurs at
the velocities and with the boundary conditions found in
sewers, particularly high during periods of storm runoff. A
description of these two states of flow is given by Chow
(3), as follows:
"Depending on the effect of viscosity relative to
inertia, the flow may be laminar, turbulent, or
transitional. In laminar flow, the water particles
appear to move in definite smooth paths, or stream-
lines, and infinitesimally thin layers of fluid
seem to slide over adjacent layers. In turbulent
flow, the water particles move in irregular paths
which are neither smooth nor fixed but which in
the aggregate still represent the forward motion
of the entire stream."
(b) Varying velocities within the section, with higher
velocities near the surface and lower velocities near the
bottom. Average velocity in the vertical is at about
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0.6 depth. Velocities are higher near the center of the
pipe or conduit than near the outer boundaries. Such veloc-
ity distributions are generally characteristic of open-
channel flow conditions, but are not valid when the sewer
becomes surcharged.
(c) The tendency for flows transporting materials of dif-
ferent density, and having different temperatures, to remain
separate from each other for quite some distance following
their convergence.
(d) The fact that substances in solution may well behave
independently of suspended particles. Little is known of
the lateral dispersion of solutions in sewage. Conversions
from solution to suspension, and the reverse, would occur
under some conditions.
(e) Vertical drops, chutes, or hydraulic jumps a short dis-
tance upstream from the section which will produce violent
turbulence, resulting in improved distribution of suspended
solids in the cross-section.
Suspended solids heavier than water have their lowest con-
centrations near the surface, and the concentration in-
creases with depth. Near the bottom of the sewer may occur
a "bed load" composed almost entirely of heavier solids.
This may "slide" along the bottom or, with insufficient flow
velocity, may rest on the bottom. As the velocity and tur-
bulence increase, the "bed load" may be picked up and sus-
pended in the sewage.
At the beginning of storm runoff, as water picks up solids
which have accumulated in the sewer upstream during periods
of no rainfall, the flow may be composed largely of sewage
solids, or "bed load", which appears to be pushed ahead by
the water.
Suspended materials lighter than water, such as oils and
greases, float on the surface, as do leaves, limbs, boards,
bottles, and cloth and paper materials. Other small, light
particles are moved randomly within the flow by turbulence.
These may be well distributed in the cross-section without
significant effect of variable velocity within the section.
Larger, heavier suspended and floating solids tend to move
to the outside of a horizontal curve as a result of centrif-
ugal inertia force. Particles with a specific gravity much
less than 1.00 may tend to move toward the inside of the
curve. Because the effect of curvature on flow often con-
tinues downstream a considerable distance, it is probable
that a normal distribution of suspended matter is not found
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on a curve, or downstream for a distance of several sewer
widths.
Incoming sewage from an upstream lateral with different
density and temperature may not mix well, and often flows
for long distances without combining with the main body of
the sewer. The appearance may be of two streams flowing
side-by-side, each with different quality characteristics.
A sample taken from either stream is not representative of
the entire stream character.
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SECTION IV
REQUIREMENTS AND PURPOSES OF SAMPLING
Sampling of sewage is performed to satisfy various purposes
and requirements. These include the planning, design and
operation of facilities for the control and treatment of
sewage; the enforcement of water quality standards and ob-
jectives; and general research to increase our knowledge of
the characterization of sewage.
Development of a program of sampling is presently based on
a limited number of properties and constituents for which
analyses are made. The type of sample collected depends on
the purpose of the program, and on both technical and eco-
nomic considerations.
COMMON PROPERTIES AND CONSTITUENTS
Although the constituents of sewage include most substances
known to man, there are a limited number of analyses made to
determine the more common properties and constituents. Most
of these are shown in Table 2, which is taken from (4) with
the addition of bacteria and TOG parameters, and of the col-
umn on required sample sizes. Columns of the table provide
information as follows:
Column 1 - Specific sewage parameter.
Column 2 - Preservative essential to sustaining the charac-
ter of sewage as sampled between the time of sampling and
the time of making the analysis.
Column 3 - The maximum period for holding the sample prior
to the analysis. This is the allowable period after the
preservative has been applied.
Column 4 - Approximate required sample size. This can be
considered only a very rough figure to assist in designing
a sampling program. In some cases there may be a difference
in the size of sample required for a given parameter, de-
pending on the method of analysis to be used.
Figures given for sample size are generally large. For ex-
ample, much smaller samples are needed with use of various
systems of automatic analysis. The Technicon Auto-Analyzer
requires samples of less than 30 ml, and is recommended for
total alkalinity, chloride, cyanide, fluoride, total hard-
ness, nitrogen (ammonia), nitrogen (Kjeldahl), nitrogen
(nitrate - nitrite), phosphorus, sulfate, COD, and others.
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a>
to
u
I
TABLE 2. Properties and Constituents of Sewage
Approxlmate
Parameter
Aeidity-Alkalinity
Ii9che>ical Oxygen Demand (3-day)
Calcium
Ch««lcal Oxygen Demand
Chloride
Bacteria -
lacterla - fecal collform, total collform, or
fecal streptococcus
Color
Cyanide
Dissolved Oxygen
Fluoride
Hardness
•Metal., Total
"Metals. Dissolved
Nitrogen, Ammonia
Nitrogen, Kjeldahl
Nitrogen, Nitrate - Nitrite
Oil and Grease
Organic Carbon (Total and Dissolved)
Phenolic*
Phosphorus
Solids (total, dissolved, suspended,
Specific Conductance
Sulfata
Sulfide
Threshold Odor
Turbidity
volatile)
Preservative
Refrigeration at 4°C
Refrigeration at 4°C
None Required
2 ml H2S04 per liter
None Required
Maintain temperature as at source -
usually requires refrigeration
Refrigeration at 4 ° C
NaOH to pH 10
Determine on site
None Required
None Required
5 ml HNOj per liter
Filtrate: 3 «1 Isl HN03 per liter
40 mg HgClj per liter - 4 ° C
40 mg HgClj per liter - 4°C
40 rag HgClj per liter - 4°C
2 ml H-SO, per liter - 4°C
2 ml H2SOA per liter (pH 2)
Determine on site
1.0 g CuSO^.j^ + HjPO^ to pH 4.0 - 4°C
40 mg HgCl2 per liter - 4'C
None Available
None Required
Refrigeration at 4 " C
2 ml Zn acetate per liter
Refrigeration at 4*C
None Available
Maximum
Holding Period
24 hours
6 hours
Indefinite
7 days
Indefinite
8 hours
24 hours
24 hours
No holding
7 days
7 days
6 months
* months
7 days
Unstable
7 day s
24 hours
7 days
No holding
24 hours
7 days
7 days
7 days
7 days
7 days
24 hours
7 days
Required
Sample Slie (•!)
50-100
1000
50
50
50
200
50
500
250-300
200-300
25
109
100
100
100
100
1000
100
—
500
200
1000
--
100
1000
200
1000
* Su» of the concentrations of metals In both the dissolved and suspended fractlona.
** For deterainatlon of trace metals in solution by atonic absorption spectroscopy.
-------
TYPE OF SAMPLE
The type of sample collected depends on a number of factors
such as the rate of change of flow and of the character of
the sewage, the accuracy required, and the availability of
funds for conducting the sampling program. All samples col-
lected, either manually or with automatic equipment, are in-
cluded in the following types:
1. Manual "grab" samples which are obtained by
dipping a container into the sewer and bring-
ing up a sample of wastewater. Containers
are sometimes devised to grab a sample at a
stationary depth or so that a sample inte-
grated from bottom to top of the stream is
collected. Water flows gradually into the
container as it passed through the flow.
2. Automatic "grab", or discrete, samples which
are collected at selected intervals, and each
sample is retained separately for analysis.
Usually each sample is collected at a single
point in the sewer cross-section. However, in
a few instances samplers with multiple ports
have been used to allow simultaneous collec-
tion from several points in the cross-section.
3. Simple composite samples, which are made up of
a series of smaller samples (aliquots) of con-
stant volume collected at regular time inter-
vals and combined in a single container. The
series of samples is collected over a selected
time period, such as 24 hours, or during a
period of storm runoff, for example. The sim-
ple composite represents the average condition
of the waste during the period only if the
flow is constant.
4. Flow-proportional composite samples, which are
collected in relation to the flow volume dur-
ing the period of compositing, thus indicating
the "average" waste condition during the
period. One of two ways of accomplishing this
is to collect samples of equal volume, but at
time intervals which are inversely proportional
to the volume of flow. That is, the time in-
terval between samples is reduced as the volume
of flow increases, and a greater total sample
volume is collected. Flow proportioning can
also be achieved by increasing the volume of
17
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each sample collected in proportion to the
flow, but keeping the time interval between
samples constant.
5. Manually composited samples which are ob-
tained, where recording flow records are
available, from fixed volume "grab", or dis-
crete, samples collected at known times and
proportioned manually to produce a flow pro-
portioned composite sample.
6. Sequential composite samples, which are com-
posed of a series of short-period composites,
each of which is held in an individual con-
tainer. For example, each of several samples
collected during a 1-hour period may be com-
posited for the hour. The 24-hour sequential
composite is made up from the individual 1-hour
composites.
ADEQUACY OF A SAMPLING PROGRAM
The adequacy of a sampling program depends largely on the
optimum selection of sampling sites. Both the program cost
and its effectiveness in collecting samples representative
of the character of sewer flows are seriously affected by
the care exercised in site selection. Similarly, the kinds
of samplers selected determine the adequacy of the program
with respect to obtaining suitable data for the needs of
the particular sampling program.
In most cases, use of mathematical statistical analysis for
determining the probable errors in the data obtained by
sewer sampling is not practical. A single "grab" sample of
1 liter, even in dry-weather flows, is not necessarily indi-
cative of the average character of the flow. With respect
to an instant of time, the indicated character of the sewage
may vary with the point in the cross-section from which it
was "grabbed". One must consider the universe of sewage
volumes represented by the sample. At the instant of sam-
pling, it may be all the liters of sewage in the cross-
section at that instant. But, if the sewage is not
thoroughly mixed, we know that the sample is biased, that
is, it may represent only a portion of the 1-liter samples
in the cross-section, possibly only those near the surface
of the flow.
18
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In periods of storm runoff, it is known, if only by obser-
vation, that the character of the sewage is continually
changing, possibly with great rapidity. There then becomes
no single universe represented by the "grab" sample. In-
stead, there is an infinite number of universes, and the
single "grab" sample is without meaning in determining the
character of the sewage. A similar situation exists in the
case of sewers carrying industrial wastes. The variability
of flow and of quality parameters during periods of storm
runoff are illustrated in figure 1, wherein quantity and
quality data for a storm on the Bloody Run sewer watershed
at Cincinnati, Ohio, are graphically presented.
It becomes apparent, then, that a large number of samples
is required to adequately characterize the character of
sewage in a combined sewer during and immediately after a
storm event, particularly if the character is to be related
to flow rate. Compositing the samples in proportion to
flow rate may determine the average character of the sewage
during the period of compositing. However, it does nothing
to describe the pattern of changes which may occur during
that period.
Awareness of the general character of sewer flows and of
flow modes in storm sewers and combined sewers, and knowl-
edge of the variability of pollutant concentration, leads to
an understanding of how best to select sites for sampling.
Some of the considerations in making such selections are:
1. Maximum accessibility and safety — Manholes
on busy streets should be avoided if possible;
shallow depths with manhole steps in good con-
dition are desirable. Sites with a history of
surcharging and/or submergence by surface
water should be avoided if possible. Avoid
locations which may tend to invite vandalism.
2. Be sure that the site provides the information
desired — Familiarity with the sewer system
is necessary. Knowledge of the existence of
inflow or outflow between the sampling point
and point of data use is essential.
3. Make certain the site is far enough downstream
from tributary inflow to ensure mixing of the
tributary with the main sewer.
4. Locate in a straight length of sewer, at least
six sewer widths below bends.
19
-------
140
"£ 130
«*-
u
^ 120
<
5 no
w>
o
100
90'
2300
2330
0030
800
700
600
*— %
1 500
o 400
o 300
o
ta
200
100
COD
BOD
2300
2330
2*tOO
0030
2300
2330
0030
Figure 1. Runoff Quantity and Quality Data,
Bloody Run Sewer Watershed*
Taken from Reference 17.
20
-------
5. Locate at a point of maximum turbulence, as
found in sewer sections of greater roughness
and of probable higher velocities. Locate
just downstream from a drop or hydraulic jump,
if possible.
6. In all cases, consider the cost of installation,
balancing cost against effectiveness in pro-
viding the data needed.
Presently available sewage samplers have a great variety of
characteristics with respect to size of sample collected,
lift capability, type of sample collected (discrete or com-
posite) , material of construction, and numerous other both
good and poor features. A number of considerations in
selection of a sampler are:
1. Rate of change of sewage conditions
2. Frequency of change of sewage conditions
3. Range of sewage conditions
4. Periodicity or randomness of change
5. Availability of recorded flow data
6. Need for determining instantaneous conditions,
average conditions, or both
7. Volume of sample required
8. Need for preservation of sample
9. Estimated size of suspended matter
10. Need for automatic controls for starting and
stopping
11. Need for mobility or for a permanent
installation
12. Operating head requirements.
Because of the variability in the character of storm and/or
combined sewage, and because of the many physical diffi-
culties in collecting samples to characterize the sewage,
precise characterization is not practicable, nor is it pos-
sible. In recognition of this fact, one must guard against
embarking on an excessively detailed sampling program, thus
21
-------
increasing costs, both for sampling and for analyzing the
samples, beyond costs that can be considered sufficient for
conducting a program which is adequate for the intended
purpose.
A careful study of costs should be made prior to commencing
a program of sampling, balancing cost against the number of
samples and analyses required for adequate characterization
of the wastewater. As the program progresses, current study
of the results being obtained may make it reasonable to re-
duce or increase the number of samples collected.
The unit cost of handling and analyzing samples can often be
reduced by careful planning and scheduling of field work,
and by coordination with laboratory requirements. If the
volume of samples is large, and the program is to continue
over a long time period, consideration should be given to
use of equipment for automatic analyses and in-situ monitor-
ing. A number of equipment types and methods, such as spe-
cific ion electrodes and probes, are available for these
purposes. As an example, approximately 15 samples per hour
can be analyzed for chloride, using the Technicon Auto-
Analyzer. Samples of only 4 ml volume are required. Cau-
tion is needed in selecting equipment suitable for a series
of parameters for which analyses are to be made. With some
equipment, the time required for making necessary adjust-
ments between each of a series of tests may counteract the
rapidity of making analyses for a single parameter.
SPECIFIC SAMPLING PURPOSES AND REQUIREMENTS
Sampling programs are set up for various purposes for which
the requirements are not necessarily the same. That is,
parameters important to one kind of project may not be
needed for another project having a different objective.
As an example, parameters of interest for operation of
facilities for control and treatment of stormwater and/or
combined sewage may be more limited in number than those
needed for planning and design of the facilities. In the
operation stage, experience at the particular location and
with the unique facilities, may have demonstrated a more
limited sampling need. On the other hand, where stormwater
is combined with industrial wastes, analyses for additional
parameters may be required.
A number of physical, chemical, combinations of physical-
chemical, and biological methods have been considered in
the Storm and Combined Sewer Pollution Control Program of
22
-------
the EPA for treatment of stormwater and combined sewage. In
most cases, some type of control such as reduction of instant-
aneous peak flows is essential for practical application of
treatment methods. These include storage facilities of many
types, flow regulation and routing, and remote flow and overflow
sensing and telemetering.
Specific processes which have been investigated are (5):
Physical - (1) Fine mesh screening; (2) Microstrainer; (3)
Screening/Dissolved-air flotation; (4) High-rate single-,
dual, or tri-media filtration; (5) Swirl and helical separa-
tion; (6) Tube settlers; etc.
Chemical - (1) Coagulant and polyelectrolyte aids for sedimenta-
tion, filtration, flotation and microstraining; (2) Chemical
oxidation and use of ozone for oxidation; and (3) Disinfection
— chlorination, ozonation, high rate application, on-site gene-
ration, and use of combined halogens (chlorine and iodine) and
chlorine dioxide.
Physical-Chemical - (1) Screening plus dissolved-air flotation
with flotation aids; (2) Screening - chemical flocculation -
sedimentation - high-rate filtration; (3) Powdered and granular
activated carbon adsorption; (4) Chemical flocculation - tube
sedimentation - tri-media filtration; and (5) Screening - coag-
ulation - high rate dual-media filtration.
Biological - (1) High-rate plastic and rock media trickling
filters; (2) Bio-adsorption (contact stabilization); (3)
Stabilization ponds; (4) Rotating biological contactor; and (5)
Deep-tank aerobic and anaerobic treatment.
For planning and designing such facilities and processes, and
for testing their impact on receiving streams, sampling for
certain basic wastewater parameters is essential. In general
these include:
1. Biochemical oxygen demand (BOD) - Used to determine
the relative oxygen requirement of the wastewater.
Data from BOD tests are used for the development
of engineering criteria for the design of waste-
water treatment plants.
2. Chemical oxygen demand (COD) - Provides addi-
tional information concerning the oxygen re-
quirement of wastewater. It provides an in-
dependent measurement of organic matter in
23
-------
the sample, rather than being a substitute
for the BOD test. For combined sewer over-
flows and stormwater, COD may be more repre-
sentative of oxygen demand in a receiving
stream because of the presence of metals
and other toxicants which are relatively
non-biodegradable.
3. Total oxygen demand (TOD) - A recently devel-
oped test to measure the organic content of
wastewater in which the organics are converted
to stable end products in a platinum-catalyzed
combustion chamber. The test can be performed
quickly, and results have been correlated with
the COD in certain locations.
4. Total organic carbon (TOG) - Still another
means of measuring the organic matter present
in water which has found increasing use in re-
cent times. The test is especially applicable
to small concentrations of organic matter.
5. Chloride - One of the major anions in water
and sewage. The concentration in sewage may
be increased by some industrial wastes, by
runoff from streets and highways where salt
is used to control ice formation, salt water
intrusion in tidal areas, etc. A high chlo-
ride content is injurious to vehicles and
highway structures, and may contaminate water
supplies near the highway.
6. Nitrogen Series - A product of microbiologic
activity, is an indicator of sewage pollution,
or pollution resulting from fertilizers, auto-
mobile exhausts, or other sources. Its pres-
ence may require additional amounts of chlorine,
or introduction of a nitrogen fixation process,
in order to produce a free chlorine residual
in control of bacteria.
7. pH - The logarithm of the reciprocal of hydro-
gen ion activity. State regulations often
prescribe pH limits for effluents from indus-
trial waste treatment plants. Provides a con-
trol in chemical and biological treatment
processes for wastewater.
24
-------
8. Solids (Total, Suspended, Volatile, and
Set tleable) - Usually represent a large frac-
tion of the pollutional load in combined
sewage. Inorganic sediments, in a physical
sense, are major pollutants, but also serve
as the transporting or catalytic agents that
may either expand or reduce the severity of
other forms of pollution (6).
9. Oil and Grease - Commonly found in sanitary
sewage, but also appear in industrial wastes
as a result of various industrial processes.
Present a serious problem of removal in waste-
water treatment facilities.
10. Bacterial Indicators (Total Coliform, Fecal
Coliform, Fecal Streptococcus) - Indicate the
level of bacterial contamination.
Where more exotic wastes are combined with stormwater and
sanitary sewage, additional treatment facilities may be
required for the removal of industrial byproducts and
nutrients such as cyanide, fluoride, metals, pesticides,
nitrogen, phosphorus, sulfate and sulfide. For planning
and design of such treatment facilites, additional analyses
are required in accordance with the pollutant material
expected in the wastewater. This may, in turn, require
significant expansion of the sampling program.
Sampling and analyses of wastewater are necessary to the
satisfactory operation of treatment plants. Pollutants in
the incoming storm sewer or combined sewer are compared with
those in the effluent from the treatment plant to determine
the effectiveness of the treatment process. Additionally,
sampling of the receiving stream before and after treatment/
control system installation indicates the benefits gained
from the installation. Knowledge of the concentration of
pollutants entering the plant can be used also to make ad-
justments to the treatment process as required. Continuous
monitoring of the stream below the treatment/control facil-
ity is important to facility operation. Depending on the
type or types of treatment process used, the number of
parameters required for sampling and analyses is usually
less than those required for planning and design. For exam-
ple, where treatment consists only of sedimentation and
chlorination, analyses for oxygen demand, suspended solids,
bacterial indicators, and for chlorine residual may be suf-
ficient. If chemicals are used to assist the sedimentation
process, determination of pH may be needed. The sampling
program can be determined largely in accordance with previ-
ous experience and knowledge of the pollutants found.
25
-------
Sampling programs should start long before installation of
combined sewer overflow and stormwater treatment/control
facilities to establish the objectives of the facilities and
to provide necessary design and operation criteria. A much
longer time period for sampling may be required than antici-
pated because of the need to sample during periods of storm
runoff, which may be few in drought years.
In some cases, the availability of historical quality data
may provide a basis for prediction of future character for
planning and design purposes. Dependence on such predicted
data is not sufficient, and collection of current data is
required to verify predictions and, later, to measure facil-
ity effectiveness.
Programs of sampling and analyses of wastewater in storm
and/or combined sewers are frequently used for the enforce-
ment of water quality standards or objectives. Such pro-
grams provide information leading to the source of various
types of pollution. Often, the wastewater is continually
monitored to check on compliance with pollution control laws
and regulations. The range of different parameters to be
measured for these purposes is continually expanding with
the development of new processes. There appears to be no
limit to future analytical requirements.
26
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SECTION V
DESIRABLE EQUIPMENT CHARACTERISTICS
Having reviewed some of the vagaries of the storm and com-
bined sewer sampling problem in the preceding sections, it
is intuitively obvious that a single piece of equipment can-
not exist that is ideal for all sampling programs in all
storm and combined sewer flows of interest. One can, how-
ever, set down some general requirements for sampling equip-
ment that is to be used in the storm or combined sewer
application.
EQUIPMENT REQUIREMENTS
The success of an automatic sampler in gathering a repre-
sentative sample starts with the design of the sampler in-
take. This obviously will be dependent upon conditions at
the particular site where the sample is to be extracted.
If one is fortunate enough to have a situation where the
sewer flow is homogeneous with respect to the parameters
being sampled, then a simple single point of extraction for
the sample will be adequate. In the more typical case, how-
ever, there is a spatial variation in the concentration of
the particular constituent that is to be examined as part
of a sampling program, and then the sampling intake must be
designed so that the sample which is gathered will be nearly
representative of the actual flow. Several different designs
have been utilized in an attempt to meet this objective.
However, none can be considered as ideal or universally ap-
plicable. In a rather comprehensive study reported in (7),
the characteristics of the sampler orifice geometry were ex-
amined with particular regard to the ability of the sampler
to gather a representative sample of suspended solids. Among
parameters varied were size of orifice, shape of orifice and
intake velocity. All orifices were located in a vertical
plate forming paTt of the wall of the test section of the
flume which was used for this study. The sample flow was
therefore extracted at right angles to the stream flow. The
major conclusion that was reached by the investigators was
that, as far as suspended solids were concerned, the geometry
of the orifice at most played a secondary role and that the
most representative samples were obtained when the sampler
intake tube velocity was equal to the free stream velocity.
In situations where flow velocity gradients are strongly
present, this observation must be taken into account in the
design of a proper sampler intake.
27
-------
The automatic sampler must be capable of lifting the sample
to a sufficient height to allow its utilization over a rather
wide range of operating heads. It would appear that a mini-
mum sample lift of 15 feet or so is almost mandatory in
order to give a fairly wide range of applicability. It is
also important that the sample size not be a function of
the sample lift; that is, the sample size should not become
significantly less as the sample lift increases.
The sample line size must be large enough to give assurances
that there will be no plugging or clogging anywhere within
the sampling train. However, the line size must also be
small enough so that complete transport of suspended solids
is assured. Obviously, the velocities in any vertical sec-
tion of the sampling train must well exceed the settling
velocity of the maximum size particle that is to be sampled.
Thus, the sample flow rate and line size are connected and
must be approached together from design considerations.
The sample capacity that is designed into the piece of
equipment will depend upon the subsequent analyses that the
sample is to be subjected to and the volumetric requirements
for conducting these analyses. However, in general, it is
desirable to have a fairly large quantity of material on
hand, it being safer to err on the side of collecting too
much rather than too little. As a minimum, it would seem
that at least a pint and preferably a liter of fluid would
be desirable for any discrete sample. For composite samples
at least a gallon and preferably two (4 to 8 liters) should
be collected.
The controls on the automatic sampler should allow some
degree of freedom in the operation and utilization of the
particular piece of equipment. A built-in timer is desir-
able to allow preprogrammed operation of the equipment.
Such operation would be particularly useful, for example,
in characterizing the buildup of pollutants in the early
stages of storm runoff. However, the equipment should also
be capable of taking signals from some flow measuring device
so that flow proportional operation can be realized. It is
also desirable that the equipment be able to start up auto-
matically upon signal from some external device that might
indicate the onset of storm flow phenomena such as an ex-
ternal rain gauge, flow height gauge, etc. Flexibility in
operation is very desirable.
A power source will be required for any automatic sampler.
It may take the form of a battery pack or clock type spring
motor that is integral to the sampler itself. It may be
28
-------
pressurized gas, air pressurized from an external source, or
electrical power, depending upon the availability at the
site.
In addition to being able to gather a representative sample
from the flow, the sampling equipment must also be capable
of transporting the sample without pre-contamination or
cross-contamination from earlier samples or aliquots and of
storing the gathered sample in some suitable way. As was
noted in section IV, chemical preservation is required for
certain parameters that may be subject to later analyses,
but refrigeration of the sample is also required and is
stated as the best single means of preservation.
DESIRABLE FEATURES
In addition to the foregoing requirements of automatic sam-
pling equipment, there are also certain desirable features
which will enhance the utility and value of the equipment.
For example, the design should be such that maintenance and
troubleshooting are relatively simple tasks. Spare parts
should be readily available and reasonably priced. The
equipment design should be such that the unit has maximum
inherent reliability. As a general rule, complexity in
design should be avoided even at the sacrifice of a certain
degree of flexibility of operation. A reliable unit that
gathers a reasonably representative sample most of the time
is much more desirable than an extremely sophisticated com-
plex unit that gathers a very representative sample 10 per-
cent of the time, the other 90 percent of the time being
spent undergoing some form of repair due to a malfunction
associated with its complexity.
It is also desirable that the cost of the equipment be as
low as practical both in terms of acquisition as well as
operational and maintenance costs. For example, a piece of
equipment that requires 100 man-hours to clean after each
24 hours of operation is very undesirable. It is also
desirable that the unit be capable of unattended operation
and remaining in a standby condition for extended periods
of time.
The sampler should be of sturdy construction with a minimum
of parts exposed to the sewage or to the highly humid, cor-
rosive atmosphere associated directly with the sewer. It
should not be subject to corrosion or the possiblity of sam-
ple contamination due to its materials of construction. The
sample containers should be capable of being easily removed
and cleaned; preferably they should be disposable.
29
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PROBLEM AREAS
The sampler by its design must have a maximum probability
of successful operation in the very hostile storm and com-
bined sewer environment. It should offer every reasonable
protection against obstruction or clogging of the sampling
ports and, within the sampler itself, of the sampling train.
It is in a very vulnerable position if it offers any signif-
icant obstruction to the flow because of the large debris
which are sometimes found in such waters. The unit must be
capable of operation under the full range of flow conditions
which are peculiar to storm and combined sewers and this
operation should be unimpeded by the movement of solids with-
in the fluid flow. If the unit is to be designed for opera-
tion in a manhole, it almost certainly should be capable of
total immersion or flooding during adverse storm conditions
which very frequently cause surcharging in many manhole
areas. It is also necessary that the unit be able to with-
stand and operate under freezing ambient conditions, and
that it be able to withstand the high flow velocities and
the associated high momentums found in storm and combined
s ewer flows.
Probably one of the most significant problem areas lies in
the attempt to gather a sample that is representative of
low as well as high specific gravity suspended solids. The
different momentum characteristics call for differing ap-
proaches in sampler intake design and in intake velocities.
Another problem area arises in a sampling program where it
is desirable to sample floatable solids and materials such
as oils and greases as well as very coarse bottom solids
and bed load proper.
For samples which are to be analyzed for constituents which
require chemical fixing soon after the sample is collected,
there are other problems. Although it is true that the re-
quired amount of fixing agent could be placed in the sample
container prior to placing it in the field, for composite
samples in particular, where the eventual total sample is
built up of smaller aliquots gathered over an extended
period of time, the initial high concentrations of the
fixing agent as it becomes mixed with the early aliquots
may well be such as to render the entire sample unsuitable
for its intended purpose.
30
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The precision of the analyses that the sample is to be subjected
to should also be kept in mind by the designer of the equipment.
For example, in (4) it is noted that 77 analysts in 53 labora-
tories analyzed natural water samples plus an exact increment of
biodegradable organic compounds. At a mean value of 194 milli-
grams per liter BOD, the standard deviation was plus or minus 40
milligrams per liter. This points out again the need for the
designer to look at the left as well as the right of the decimal
point.
Adsorption of certain pollutants by materials of the sampler train
or sample container may result in a non-representative sample.
31
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SECTION VI
REVIEW OF COMMERCIALLY AVAILABLE AUTOMATIC SAMPLERS
INTRODUCTION
Although some types of automatic liquid sampling equipment
have been available commercially for some time, project
engineers continue to design custom sampling units for their
particular projects due to a lack of commercial availability
of suitable equipment. In the last few years, however,
there has been a proliferation of commercial sampling equip-
ment designed for various applications. In the present sur-
vey, after a preliminary screening, over 30 prospective
sampler manufacturers were contacted. Although a few of
these companies were no longer in business, it was much more
typical that new companies were being formed and existing
companies were adding automatic sampling equipment to their
product lines. In addition to their standard product lines,
most manufacturers of automatic sampling equipment provide
special adaptations of their equipment or custom designs to
meet unique requirements of certain projects. Some designs
which b.egan in this way have become standard products, and
this can be expected to continue.
The products themselves are rapidly changing also. Not only
are improvements being made as field experience is gathered
with new designs, but attention is also being paid to cer-
tain areas that have heretofore been largely ignored. For
example, one company is introducing sampling probes that
allow gathering oil or various other liquids from the flow
surface, and the like.
In view of the burgeoning nature of this product area, it is
inevitable that some ommissions have been made. Obviously,
it would be presumptive to state that this survey is com-
plete in every detail. For example, one company that was
contacted expects to expand its product line from about
15 models to over 30 models in the near future.
In order to facilitate the reader's comparison of the over
50 models of automatic samplers that are presented, a common
format has been designed. A few words about the headings of
this format are in order.
Designation; Identifies the particular sampler
model that is being considered. In
some instances several models are
described under the same general
33
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Manufacturer:
Sampler Intake:
Gathering Method
S ample Lift:
Line Size:
heading. This occurs when there
does not appear to be a fundamental
difference in the basic principles
of operation but rather the manu-
facturer has chosen to give sepa-
rate designations based upon the
addition of certain features such
as refrigeration, a weather-proof
cas e, etc.
Lists the company that supplies the
particular model
address, and its
in question, its
telephone number
Describes the part of the sampler
that actually extracts fluid from
the stream being sampled. It may
be, for example, a supplied custom
designed intake probe, a dipping
bucket or scoop, etc. However,
many of the samplers do not provide
any form of intake other than the
end of a tube through which a sam-
ple is to be transported to the
equipment.
Addresses the method for gathering
the sample and transporting it to
its container. Three basic cate-
gories are identified: Mechanical,
where dippers, scoops, etc. are
utilized; Suction Lift, employing
either evacuated vessels, vacuum
pump, or mechanical pump; and
Forced Flow, utilizing pneumatic
ejection, a submerged pump, etc.
maximum practical
that the particular
piece of equipment is
operation.
Addresses the
vertical lift
capable of in
Describes the minimum line diameter
of the sampling train wherever it
may occur in the particular piece
of equipment. Due to the presence
of tube fittings, screens, valves,
etc. in some designs, it does not
necessarily represent maximum
particle size.
34
-------
Sample Flow Rate;
Sample Capacity;
Controls:
Power S ource:
Sample Refrigerator;
Construction Materials
Gives the flow rate of the sample
as it is being transported within
the sampling train of the piece of
equipment in question.
Addresses the size of the sample
that is being collected. In the
case of composite samplers, the
aliquot size is also given.
Addresses those controls within the
sampler that can be utilized to
vary its method of operation. For
example, built-in timers, inputs
from external flowmeters, etc.
Gives power source or sources that
may be utilized to operate the
equipment.
Addresses the type of cooling that
may be available to provide pro-
tection to collected samples.
Primary attention here has been
devoted to the sampling train
proper, although certain other
materials such as case construction
are also noted.
Basic Dimensions:
The overall package is described
here in order to give the reader a
general feel for the size of the
unit. For those units which might
be considered portable, a weight is
also given. For units that are de-
signed for fixed installations only,
this fact is also noted.
Base Price:
General Comments:
The base price as quoted and effec-
tive in August 1972 is given here.
Certain options or accessories that
may be of general interest are also
included with their prices.
Here any additional comments that
are felt to be pertinent to the
particular piece of equipment in
question are given. This includes
any additional descriptions that
35
-------
are felt necessary in order to
understand better the operating
principles that are involved. Also
included are certain performance
claims that may be made by the
manufacturer.
In general, the commercially available automatic samplers
have been designed for a particular type of application.
In the present work, however, they are being considered for
application in a storm or combined sewer setting. Because
of the vagaries of such an application as outlined in sec-
tions III and IV of this report, it is altogether possible
that a particular unit may be quite well suited for one
particular application and totally unsuitable for use in
another. It is not the intention of this report to endorse
any particular piece of equipment. Rather, they are being
compared and evaluated for their suitability in general in
a storm or combined sewer application. This evaluation
takes the form of 12 points which are addressed for each
model sampler that has been considered. They are the
following:
1. Vulnerability to obstruction or clogging of sam-
pling ports, tubes and pumps.
2. Obstruction of main stream flow and susceptibility
to damage.
3. Operation under the full range of flow condi-
tions peculiar to storm and combined sewers.
4. Operation unimpeded by the movement of solids
such as silt, sand, gravel and debris within the
fluid flow; including durability.
5. Automatic start-up and operation (during storm
conditions), unattended, self-cleaning.
6. Flexibility of operation allowed by control
sys tern.
7. Collection of samples of floatable materials,
oils and grease, as well as coarser bottom
solids.
8. Storage, maintenance and protection of collected
samples from damage and deterioration as well as
freedom of the sample train and containers from
precontamination, adsorption, etc.
36
-------
9. Amenability to installation and operation in
confined and moisture laden places such as
sewer manholes.
10. Ability to withstand total immersion or
flooding during adverse flow conditions.
11. Ability to withstand and operate under
freezing ambient conditions.
12. Ability to sample over a wide range of
operating head conditions.
DESCRIPTIVE FORMS AND EVALUATIONS
The descriptive forms and evaluations, as discussed above,
are presented in the following pages for various commercially
available automatic samplers. The arrangement is alphabet-
ical, and an index is provided on pages viii and ix.
37
-------
Designation:
Manufacturer:
Sampler Intake:
Gathering Method
Sample Lift;
Line Size:
Sample Flow Rate
Sample Capacity;
Controls:
Power Source:
Sample Refrigerator;
Construction Materials
Basic Dimensions:
Base Price:
BIF SANITROL FLOW-RATIO MODEL 41
BIF Sanitrol
P.O. Box 41
Largo, Florida 33540
Phone (813) 584-2157
Dipping bucket
Mechanical; dipper on sprocket-
chain drive.
16 inches to 16 feet
1" O.D. tube connects collection
funnel to sample container.
Not applicable
Dipping bucket holds 1 ounce;
user supplies sample composite
container to suit.
Sampling cycle can either be
started at fixed, selected inter-
vals from a built-in timer (15,
7.5, 3.75, or 1.88 minutes) or in
response to signals from an exter-
nal flow meter.
115V ac
Separate automatic refrigerated
sample compartment with two
1-gallon jugs available.
Dipper and funnel are stainless
steel; sprockets and chain are
stainless steel; enclosure is
fiberglass.
Upper portion is 9 3/8"W x 9 1/4"D
x 8"H; lower portion is 9 3/8"W
x 4"D; fixed installation.
$545 with 16" mild steel chain plus
$40 per foot for additional length.
$595 with 16" stainless steel chain
plus $50 per foot for additional
length.
38
-------
to
Figure 2. BIF Sanitrol Flow - Ratio Model Al Sampler
Photograph courtesy of BIF Sanitrol.
-------
General Comments: Manufacturer states unit was de-
signed to sample raw or effluent
wastes. A heavy duty model is
available for applications where
mixed wastes are present such as
a paper mill where wood chips and
fiber are present in waste liquid
BIF Sanitrol Flow-Ratio Model 41 Evaluation
1. Clogging of sampling train is unlikely; however, the
exposed chain-sprocket line is vulnerable to jamming
by rags, debris, etc.
2. Unit provides a rigid obstruction to flow.
3. Unit should operate over full range of flows.
4. Movement of solids could jam unit.
5. No automatic starter; no self cleaning features.
6. Collects fixed size aliquots paced by built-in timer
and composits them in a suitable container.
7. Does not appear well suited for collecting either
floatables or coarser bottom solids.
8. No sample collector provided. Optional refrigerated
sample container is available.
9. Unit is capable of manhole operation.
10. Unit cannot withstand total immersion.
11. Unit is not suitable for prolonged operation in
freezing ambients.
12. 16 foot maximum lift puts some restriction on
operating head conditions.
40
-------
Designation;
Manufacturer:
Sampler Intake;
Gathering Method:
Sample Lift;
Line Size:
Sample Flow Rate;
Sample Capacity:
Controls;
P ower S ource:
Sample Refrigerator;
Construction Materials
Basic Dimensions
Base Price;
General Comments
BRAILSFORD MODEL DC-F
Brailsford and Company, Inc.
Milton Road
Rye, New York 10580
Phone (914) 967-1820
End of 6 foot long sampling tube;
weighted and fitted with 50 mesh
strainer.
Suction lift by positive displace-
ment pump .
Pump is capable of 10 foot lift
but manufacturer recommends that
lift be restricted to 3 to 7 feet.
Appears to be 1/4" I.D.
Adjustable from about 0.1 to
0.6 cubic inches per minute.
Pump output is collected in a
2-gallon jug.
Pump stroke is adjustable by means
of a slotted yoke on the piston
rod. On/Off Switch.
6V dc dry cell battery
N one
Stainless steel, teflon, vinyl,
polyethylene; case is laminated
Formica-wood construction, plastic
rain boot.
12"W x 9 1/2"H; weighs 19 pounds
empty; portable.
$281.
Pump is valveless oscillating
cylinder type. No lubrication is
required for the life of the unit.
Driven by a brushless dc motor of
patented design with a service life
41
-------
In excess of 3,000 hours. Contin-
uous running pump is automatically
shut off when sample jug is full.
A Model DU-1 is also available at
$325. It is essentially a
Model DC-F with the addition of an
electric timer, wherein the pumping
rate can be set for any designed
frequency between one revolution
every 1.5 minutes and one revolu-
tion every 12 minutes. Model EP
is a similar unit but explosion
proof at $330.
Brailsford Model DC-F Evaluation
1. 50 mesh strainer on end of sampling tube might be
prone to clogging.
2. Minimal obstruction of flow.
3. Should operate reasonably well under all flow
conditions, but low intake velocity will affect
representativeness of sample at high flow rates.
4. Movement of solids should not hamper operation.
5. Continuous flow unit, no automatic starter, no other
self cleaning features.
6. Unit collects a continuous, low flow rate stream of
sample and composits it in a 2-gallon jug.
7. Unsuitable for collection of floatables or coarser
bot torn solids.
8. No refrigerator. Continuous flow eliminates cross
contamination.
9. Appears fairly well suited for manhole operation.
10. Cannot withstand immersion.
11. Not suited for operation in freezing ambients.
12. Recommended lift of 4 feet puts restriction on use of
unit .
42
-------
Designation;
Manufacturer:
Sampler Intake:
Gathering Method
Sample Llft:
Line Size:
Sample Flow Rate
Sample Capacity:
Controls:
Power S ource;
Sample Refrigerator;
Construction Materials
Basic Dimensions:
Basic Price:
General. Comments ;
BRAILSFORD MODEL EV
Brailsford and Company, Inc.
Milton Road
Rye, New York 10580
Phone (914) 967-1820
End of 6 foot long sampling tube
fitted with a molded plastic inlet
s coopr-s trainer to help prevent
blockage by rags, paper, etc.
Suction lift by vacuum pump.
6 feet maximum.
Appears to be 1/4" I.D.
Depends upon lift.
A 1 gallon composite sample is
accumulated from small aliquots
in 8 to 48 hours.
A control switch permits the choice
of four timing intervals which will
cause a 1 gallon sample to be
collected in either 8, 16, 24 or
48 hours.
115V ac or 12V dc
None
Sampling train is all plastic; case
is laminated Formica-wood
cons truction.
12"W x 9"D x 19"H; weighs 19 pounds
empty; portable.
$482 with dry cell battery
$583 with N. Cad battery
$625 with N. Cad battery and
ac power unit.
Unit was designed for flows with
a high percentage of suspended
solids or where volatiles are
present. Sample never passes
43
-------
Figure 3. Brailsford Model EV Sampler
Photograph courtesy of Brailsford and Company, Inc
44
-------
through pump or valves or orifices
which could become clogged. In
operation, a small vacuum pump
evacuates air from a small metering
chamber to which the sample bottle
and inlet tube are connected. When
chamber is filled to a predeter-
mined level, a magnetic sensing
switch stops the pump and opens a
vacuum relief valve so a portion of
the sample flows into the jug and
the remainder backflushes the inlet
tube.
Brailsford Model EV Evaluation
1. Specially designed inlet scoop-strainer may help
prevent blockage. Rest of sample train should be
free from clogging.
2. Minimal obstruction of flow.
3. Should operate reasonably well under all flow condi-
tions, but fairly low intake velocities could affect
representativeness of sample at high flow rates.
4. Movement of solids should not hamper operation.
5. No automatic starter - backflushing of inlet tube at
end of each cycle provides a self cleaning function
of sorts .
6. Unit collects a fixed time interval composite in a
1-gallon j ug.
7. Unsuitable for collection of floatables or coarser
bottom solids.
8. No refrigerator. Backflushing will help reduce
cross contamination.
9. Appears well suited for manhole operation.
10. Unit cannot withstand immersion.
11. Not suitable for operation in freezing ambients.
12. Maximum lift of 6 feet puts restrictions on use of
unit.
45
-------
Designation:
Manufacturer:
Sampler Intake
Gathering Method
S ample Lift:
Line Size:
Sample Flow Rate
Sample Capacity:
Controls :
BVS MODEL PP-100
Brandywine Valley Sales Company
P.O. Box 243
Honey Brook, Pennsylvania 19344
Phone (215) 273-2841
Plastic cylindrical sampling probe
which is gravity filled. A row of
small holes around the circum-
ference near the bottom forms an
inlet screen; weighted base.
Forced flow due to pneumatic
eje ction.
requires 1 pound
every 2 feet of
Up to 200 feet;
of pressure for
vertical lift.
1/8" I.D.
Depends upon pressure setting and
lift.
Sample chamber volume is
sample composited in 2
jug in standard
_ 50 ml;
r _ _ r in 2 1/2-gallon
jug in standard model or 1 1/2-gal-
lon jug in refrigerated model.
Pressure regulator connecting gas
supply is set between 5 and 140 psi
(depending upon lift required);
sampling interval timer is adjust-
able to allow from 2 seconds to
60 minutes to elapse between ali-
quots; manual on/off switch stand-
ard. Optional control package
accepts signals from external flow
meter or totalizer.
Power Source:
Sample Refrigerator
One 12-pound can of refrigerant
is standard gas source; 12V dc or
117V ac required for refrigerated
models or flow proportional control
option.
Model PPR-100 offers an absorption
refrigerator cooled sample case.
46
-------
i *
Figure A. BVS Model PP-100 Sampler
Photograph courtesy of Brandywine Valley Sales Company
47
-------
Construction Materials
Basic Dimensions:
Base Price:
General Comments:
Sampling probe is PVC standard,
teflon or stainless steel available;
plastic sampling line standard,
teflon available; polyethylene sam-
ple container; Armorhide finished
aluminum case.
Non-refrigerated - 12 1/2"W x 10"D
x 18"H. Refrigerated - 17"W
x 19 1/2"D x 17 3/4"H. Both models
portable.
$650 for basic unit including
50 ml sampling probe, one 12 pound
disposable cylinder of R-12, and
three 20-foot lengths of tubing.
Refrigerated model PPR-100 is $850.
Add $100 for winterizing system;
$250 for solid state control
package for flow proportional
operation.
Timing circuits are controlled by
fluidic and pneumatic components.
Absorption refrigerator has no
moving parts. After each aliquot
is gathered, the inlet strainer of
the sampling probe is purged by
vent pressure from timing valve.
Two year parts and labor warranty.
Alternate sampling probes available
include a surface sampling probe
for surface oil, vertical stratum
sampling probe for sampling at
6" depth intervals, and float
mounted probes for sample quantity
accuracy that is independent of
head .
BVS Model PP-100 Evaluation
1. Sampling probe is vulnerable to blockage of a number
of sampling ports at one time by paper, rags, plastic,
etc. Sampling train is unobstructed 1/8" I.D. tube
which should pass small solids. No pump to clog.
2. Unless sampling probe is clamped in place, it offers
no rigid obstruction to flow.
48
-------
3. Sampling chamber will fill immediately following intake
screen purge at end of previous cycle. Circulation of
flow through chamber would appear to be limited, re-
sulting in a sample not necessarily representative of
conditions in the sewer at the time of the next trig-
gering signal.
4. Movement of solids in flow could affect position of
sampling probe and erode plastic lines if flow is
deep enough.
5. No automatic starter. A self cleaning feature for the
intake screen is accomplished by using vent pressure
from the timing valve to purge it.
6. Collects fixed size aliquots at either preset time
intervals or paced by external flow meter if equipped
with control option and composits them in a suitable
container.
7. Special sampling probe available for surface oil sam-
pling, etc.; appears unsuitable for sampling coarser
bottom solids.
8. Automatic refrigerated sample compartment available,
but sample size is reduced. Cross contamination
appears likely.
9. Unit appears capable of manhole operation.
10. Case is weatherproof but will not withstand total
immersion.
11. Optional winterizing kit is available for use in very
cold ambients.
12. Unit has a very wide range of operating head coni-
tions. High lifts will result in faster depletion of
gas supply.
49
-------
Designation;
Manufacturer:
Sampler Intake
Gathering Method
S amp1 e Lift:
Line Size:
Sample Flow Rate
Sample Capacity:
Controls:
Power Source:
Sample Refrigerator
BVS MODEL SE-400
Brandywine Valley Sales Company
P.0. Box 243
Honey Brook, Pennsylvania 19344
Phone (215) 273-2841
PVC screen over pump inlet.
Forced flow from submersible pump
32 feet maximum.
1/2" I.D. inlet hose.
1 to 2 gpm typical.
Aliquot volume is a function of the
preset diversion time; 2 1/2 gallon
composite container is standard,
5 gallon optional.
Unit operates on a continuous flow
principle, returning uncollected
flow to waste. Sample is pumped
through a stainless steel, non-
clogging diverter valve. Upon
receiving a signal from either the
built-in timer or an external flow
meter, the unit diverts the flow
for a preset period of time (adjust-
able from 0.06 to 1.0 seconds) to
the sample container.
When operating in the timed sam-
pling mode, the sampling frequency
rate is continuously adjustable
from 0.2 seconds to 60 hours. When
operating in the flow-proportional
mode the sampler is triggered
directly by the external flow meter.
115V ac
Two sizes of automatically refrig-
erated sample compartments to
accomodate either 2 1/2 or 5-gallon
containers.
50
-------
Construction Materials; Sampling train; PVC, stainless
steel, plastic, polyethylene,
cabinet is aluminum with Armorhide
finish.
Basic Dimensions: 24"W x 24"D x 48"H on 8" legs.
Base Price; $2,600 including 2 1/2 gallon size
refrigerator, thermostatically con-
trolled heater, 20' of 13/16" O.D.
x 1/2" I.D. nylon reinforced plastic
inlet tubing, 20' of 1 3/8" O.D.
x 1" I.D. nylon reinforced plastic
tubing for waste return, clamps,
pump support bracket, pump strainer,
pump with 36' cord, and flow pro-
portional connection cable. For
5 gallon sized refrigerator add
$125; for 30 day strip chart re-
corder add $260.
General Comments; Submersible pump has magnetic drive,
is self-priming. Manufacturer
claims design will handle solids
to 3/8" diameter.
BVS Model SE-400 Evaluation
1. Large sampling screen over pump inlet can tolerate
blockage of a number of ports and still function.
Pump and tubing should be free from clogging.
2. Submersible pump and screen present an obstruction to
the flow.
3. Should be capable of operation over the full range of
flows .
4. Movement of small solids should not affect operation;
large objects could damage (or even physically destroy)
the in-water portion unless special protection is
provided by user.
5. No automatic starter since designed for continuous
flow. Continuous flow serves a self-cleaning function
of all except line from diverter to sample bottle.
51
-------
6. Collects spot samples paced either by built-in timer
or external flow meter and composits them in a suitable
container.
7. Appears unsuitable for collection of either floatables
or coarser bottom solids.
8. Automatic refrigerated sample compartment. Cross
contamination should not be too great.
9. Not designed for manhole operation.
10. Cannot withstand total immersion.
11. Can operate in freezing ambients.
12. Upper lift limit of 32 feet does not pose a great
restriction on operating head conditions.
52
-------
Designation;
Manufacturer:
Sampler Intake:
Gathering Method
S ample Lift;
Line Size:
Sample Flow Rate:
Sample Capacity:
Controls:
Power Source:
BVS MODEL SE-600
Brandywine Valley Sales Company
P.O. Box 243
Honey Brook, Pennsylvania 19344
Phone (215) 273-2841
Provided by user; sampler has 2"
sample inlet connection.
External head provided by user to
give continuous flow through
diverter.
Not applicable.
2" I.D.
Depends upon installation.
Aliquot volume is a function of the
preset diversion time; 2 1/2 gallon
composite container is standard,
5 gallon optional.
Unit operates on a continuous flow
principle, returning uncollected
flow to waste. Sample is pumped
through a stainless steel, non-
clogging diverter valve. Upon re-
ceiving a signal from either the
built-in timer or an external flow
meter, the unit diverts the flow
for a preset period of time (ad-
justable from 0.06 to 1.0 seconds)
to the sample container. When
operating in the timed sampling
mode, the sampling frequency rate
is continuously adjustable from
0.2 seconds to 60 hours. When
operating in the flow-proportional
mode the sampler is triggered
directly by the external flow
meter.
115V ac
53
-------
Sample Refrigerator: Two sizes of automatically refrig-
erated sample compartments to
accomodate either 2 1/2 or 5-gallon
containers.
Construction Materials; Sampling train; PVC, stainless
steel, plastic, polyethylene;
cabinet is aluminum with Armorhide
finish.
Basic Dimensions; 24"W x 24"D x 48"H on 8" legs.
Base Price; $2,800 including 2 1/2 gallon size
refrigerator, thermostatically con-
trolled heater, and flow propor-
tional connection cable. For
5 gallon sized refrigerator add
$125; for 30 day strip chart re-
corder add $260.
General Comments; Manufacturer claims design will
handle solids to 2" diameter.
BVS Model SE-600 Evaluation
1. Should be free from clogging. Sampling intake must be
designed by user.
2. Sampler itself offers no flow obstruction.
3. Should be capable of operation over the full range of
f low .
4. Movement of solids should not affect operation.
5. No automatic starter since designed for continuous
flow. Continuous flow serves a self-cleaning function
of all except line from diverter to sample bottle.
6. Collects spot samples paced either by built-in timer
or external flow meter and composits them in a suit-
able container.
7. Ability to collect floatables or coarser bottom solids
will depend upon intake design.
8. Automatic refrigerated sample compartment. Cross con-
tamination should not be too great.
54
-------
9. Not designed for manhole operation
10. Cannot withstand total immersion.
11. Can operate in freezing ambients.
12. Operating head provided by user.
55
-------
Designation;
Manufacturer:
Sampler Intake:
Gathering Method:
S amp1e Lift;
Line Size:
Sample Flow Rate:
Sample Capacity
Controls:
CHICAGO "TRU TEST"
Chicago Pump Division
FMC Corporation
622 Diversey Parkway
Chicago, Illinois 60614
Phone (312) 327-1020
Provided by user, a screen with
maximum openings of 1/2" is
recommended; sampler has standard
2" pipe inlet.
External head to provide flow
through a sampling chamber from
which a rotating dipper extracts
a sample aliquot and transfers it
to a funnel where it is gravity
fed to a composite bottle.
Not applicable.
Smallest line in sampling train is
the one connecting the funnel to
the sample bottle; it appears to
be about 1 inch.
Recommended flow rate through sam-
pler is 25 to 50 gpm with 35 gpm
as optimum. Minimum velocity in
inlet line (2" diameter recommended)
should be 2 feet per second. Below
25 gpm fungus growth and settling
in sampling chamber will affect the
sample quality.
Sampling dipper collects
sample; a 2 gallon
tainer is provided.
a 25 ml
composite con-
Power Source:
Constant rate sampling (between 3
and 20 samples per hour) is con-
trolled by built-in timer; flow
proportional sampling provided by
either transmitter control or
totalizer control from external
flow measuring device.
110V ac
56
-------
Sample Refrigerator; Automatic refrigerator to maintain
samples at 4° to 10°C is available
Construction Materials; Bisphenol polyester resin, poly-
propylene, stainless steel, and
polyethylene; case is laminated
fib erglass .
Basic Dimensions; 19 3/8"W x 21"D x 51 3/4"H.
Designed for fixed installation,
Base Price: $2,115 non-refrigerated.
$2,578 refrigerated.
General Comments: Sampling chamber has adjustable
weir plates to regulate the sewage
level. Manufacturer recommends
that intake line be limited to
50 feet or less in length.
Chicago "Tru Test" Evaluation
1. Should be free from clogging. Sampling intake must be
designed by user.
2. Sampler itself offers no flow obstruction.
3. Should operate well over entire range of flow
conditions .
4. Movement of solids should not hamper operation.
5. Designed for continuous operation; no automatic
starter. Continuous flow serves a self cleaning
function and should minimize cross-contamination.
6. Can collect either flow proportional or fixed time
interval composites.
7. Ability to collect samples of floatables and coarser
bottom solids will depend upon design of sampling
intake.
8. Automatic refrigeration maintains samples at 4° to
10°C. Offers good sample protection and freedom from
precontamination; sample composite bottle is sealed
to funnel with hose clamps.
9. Not designed for confined space or manhole operation.
57
-------
10. Cannot withstand total immersion.
11. Does not appear capable of prolonged exposure to
extremely cold ambient conditions.
12. Operating head is provided by user.
58
-------
Designation;
Manufacturer:
Sampler Intake:
Gathering Method;
S ample Lift;
Line Size;
Sample Flow Rate
Sample Capacity;
Controls:
Power S ource:
Sample Refrigerator:
HYDRA-NUMATIC COMPOSITE SAMPLER
Hydra-Numatic Sales Company
65 Hudson Street
Hackensack, New Jersey 07602
Phone (201) 489-4191
End of suction tube installed to
suit by user.
Suction lift from centrifugal pump.
Up to 15 feet.
1/2" I.D.
1.5 gpm.
Aliquot size is adjusted (based
upon anticipated flow rates where
external flow meter is to be em-
ployed) to fill the 5 gallon
composite container in 24 hours.
Sampler receives signals from ex-
ternal flow meter through a primary
relay and clock system, the clock
serving as a memory-collecting
impulses representing a given flow -
at which time a known, pre-set vol-
ume of sample is drawn. The volume
of sample is controlled by a finely
calibrated clock which opens a
free-port solenoid valve for a pre-
set time period thereby diverting
the flow to the sample container.
A built-in timer can be used to
pace the sampler when no flow meter
is available. It can either be
programmed if rough estimates of
daily flow variations are known or
function as a fixed time interval
p acer.
115V ac
None
59
-------
Construction Materials: Polyethylene sample container,
Tygon sampling lines with bronze
fittings and connections, bronze
valves and pump, stainless steel
available as alternate; cabinet
is stainless steel.
Basic Dimensions: 36"W x 13 1/8"D x 36"H; portable
Base Price: $1800.
Hydra-Numatic Composite Sampler Evaluation
1. Fairly large line size and "non-clog" pump should give
freedom from clogging; manufacturer recommends unit
for streams with high solids content.
2. Obstruction of flow will depend upon way user mounts
intake tube.
3. Should operate reasonably well over all flow conditions
4. Solids in the fluid flow should not impede operation.
5. No automatic starter. Continuous flow serves a self-
cleaning function.
6. Unit collects aliquots paced by external flow meter or
built-in timer and composits them in a suitable
container.
7. Collection of samples of floatables and bottom solids
would require specially designed intake by user.
8. No refrigeration available; sample would appear to be
reasonably well protected from damage.
9. Unit appears capable of operation in a high humidity
environment, but is too large to pass down a standard
manhole.
10. Unit cannot withstand total immersion.
11. Unit appears able to tolerate freezing ambients, at
least for moderate periods of time.
12. Lift limit of 15 feet poses some restrictions on use
of unit.
60
-------
Designation;
Manufacturer:
Sampler Intake:
Gathering Method:
S amp 1e Lift:
Line Size:
Sample Flow Rate
Sample Capacity:
Controls:
Power S ource:
INFILCO AUTOMATIC
Westinghouse Electric Corporation
Infilco Division
Box 2118
Richmond, Virginia 23216
Phone (703) 643-8481
Provided by user; sampler has
standard 2" pipe inlet.
External head to provide flow
through a sampling chamber from
which an oscillating dipper ex-
tracts a sample aliquot and trans-
fers it to a funnel where it is
gravity fed to a composite bottle.
Not applicable.
Smallest line in sampling train is
the one connecting the funnel to
the bottle; it appears to be about
1 inch.
Recommended flow
sampler is 10 to
rate through
20 gpm.
Sampling dipper collects a 10 or
20 ml sample; a 1 gallon composite
container is provided.
Constant rate sampling (between
1 and 15 samples per hour) is con-
trolled by built-in timer; flow
proportional sampling provided by
signal from external flow measuring
device.
115V ac
Sample Refrigerator; Automatic refrigerator to maintain
samples at 4° to 10°C is available
Construction Materials: Case is pressed steel.
Basic Dimensions:
About 2'W x 2'D x 5'H.
for fixed installation.
Designed
61
-------
Base Price: $4180; add $220 for refrigeration
and flow proportioning capability.
General Comments: Sampling chamber has adjustable
weir plates to regulate the sewage
level.
Infilco Automatic Evaluation
1. Should be free from clogging. Sampling intake must
be designed by user.
2. Sampler itself offers no flow obstruction.
3. Should operate well over entire range of flow
conditions.
4. Movement of solids should not hamper operation.
5. Designed for continuous operation; no automatic
starter. Continuous flow serves a self cleaning
function and should minimize cross-contamination.
6. Can collect either flow proportional or fixed time
interval composites. Representativeness of sample
will be a function of sample intake which is not a
part of this unit.
7. Collection of samples of floatables and coarser
bottom solids will depend upon design of sampling
intake.
8. Automatic refrigeration maintains samples at 4° to
10°C. Offers good sample protection and freedom from
precontamination.
9. Not designed for confined space or manhole operation.
10. Cannot withstand total immersion.
11. Does not appear capable of prolonged exposure to
extremely cold ambient conditions.
12. Operating head is provided by user.
62
-------
Designation;
Manufacturer:
Sampler Intake
Gathering Method
S amp 1e Lift:
Line Size;
Sample Flow Rate:
Sample Capacity;
Controls:
Power Source:
ISCO MODEL 1391
Instrumentation Specialties
Co., Inc.
P.O. Box 5347
Lincoln, Nebraska 68524
Phone (402) 799-2441
End of 22 foot suction tube in-
stalled to suit by user. When
provided with operational multi-
plexer and source selection valve,
up to four suction tubes can be
used for sampling from four dif-
ferent locations.
Suction lift from peristaltic pump.
26 foot maximum lift; 96 percent
delivery at 8 feet, 80 percent at
18 feet.
1/4" I.D.
Greater than 167 ml per minute
depending upon lift.
Sample size can be switch selected
from 70 ml to 490 ml at 3 foot
lift. Twenty-eight 500 ml sample
bottles are provided and are used
for collecting descrete samples or
four-sample composites when used
with the optional multiplexer.
The time interval between collec-
tions can be varied in 1/2 hour
increments from 1/2 to 6 hours; an
optional timer can be varied in
1/4 hour increments from 1/4 to
3 hours - both use a clock mech-
anism. Connections for an external
flow meter to collect samples on
the basis of stream flow rate are
provided.
118V ac or 12V dc
63
-------
'
,V_'i:W7*-'3ii..»i'.^»^' A *.5£~.J*i*.-' 'i4,.$&*
il^A^Sftff
v'\'. " 9"-\i\ 'f\ >, ••••! -' • • •*' it'"'f*;^*iV* i * v i
. -W**V. ...v , ,_to •-•'^i.3W:V>!.1 •>*•• v-'. i "'„!
Figure 5. ISCO Model 1391 Sampler
Photograph courtesy of Instrumentation Specialitiea Co., Inc
-------
Sample Refrigerator;
Construction Materials
Basic Dimensions
Base Price:
General Comments
Has ice cavity for cooling; will
maintain samples up to 40°F below
ambient for at least 24 hours.
All plastic construction including
insulated case, tubing, and sample
bottles; stainless steel hardware.
19 1/2" diameter x 21"H; weighs
40 pounds; portable.
$995; add $95 for N. Cad batteries,
$100 for multiplexer.
Sampler will withstand accidental
submersion for short periods of
time. All electrical and mechani-
cal components are waterproofed;
the programming unit is sealed in
a vapor-tight housing that contains
a regeneratable dessicant. Manu-
facturer claims peristaltic pump
tubing can fill more than
80,000 sample bottles before re-
quiring replacement. At least
100 500-ml samples may be taken on
a single 14-hour battery charge.
A rotating "clog-proof" funnel
delivers samples to the distributer
plate which channels them to their
individual bottles. After each
sample the pump automatically re-
verses itself to purge intake tube
and minimize cross-contamination.
ISCO Model 1391 Evaluation
1.
2.
3.
Plugging or clogging will depend
of intake line; the unobstructed
sampling line, peristaltic pump,
should pass small solids without
upon user installation
1/4" inside diameter
and "non-clog" funnel
difficulty.
Obstruction of flow will depend upon user mounting of
intake line.
Should operate reasonably well under all flow condi-
tions, but fairly low intake velocities could affect
representativeness of sample at high flow rates.
65
-------
Movement of solids within the fluid flow should not
affect operation adversely.
No automatic starter. Backflushing after taking each
sample provides a self cleaning function of sorts.
Unit with optional multiplexer and source selection
valve can sample from up to four individual locations
and composite in a single bottle. Can be paced by
either built-in timer or external flow meter and
collect 28 samples of up to 500 ml capacity each.
Unit does not appear suitable for collection
bottom solids; collection of floatables will
on user mounting of a suitable intake.
of coarser
depend
Unit affords good sample protection;
has ice cavity which will keep samples up
below ambient for over 24 hours.
insulated case
to 40°F
9. Unit comes with a harness for suspending it in
manholes .
10. Unit can withstand total immersion for short periods
of time.
11. Unit would not appear to function well after prolonged
exposure to freezing ambients.
12. Unit should be able to sample over a wide range of
operating head conditions.
66
-------
Designation:
Manufacturer:
Sampler Intake;
Gathering Method
Sample Lift;
Line Size:
Sample Flow Rate;
Sample Capacity;
Controls:
Power Source:
Sample Refrigerator;
Construction Materials
Basic Dimensions:
LAKESIDE TREBLER MODEL T-2
Lakeside Equipment Corporation
1022 East Devon Avenue
Bartlett, Illinois 60103
Phone (312) 837-5640
Specially designed scoop.
Mechanical; rotating scoop tra-
verses entire depth of flow; as
scoop is rotated out of flow the
sample drains by gravity through
the hub and into a composite sample
jar.
Unit must be in flow stream.
1/2" I.D.
Not applicable.
Scoop is shaped to gather a volume
of sample that is proportional to
the channel flow; can vary typically
from 300 to 600 ml when installed in
a Parshall flume.
Timer can be used to trigger sam-
pling cycle at any desired interval
of a 1 hour period.
115V ac
Automatic refrigerator available
which maintains sample temperature
at approximately 4°C.
Cast aluminum
sprockets and
glass or cast
plas tic pipe,
bottle.
frame, steel
chain drive, plexi-
aluminum scoop,
polyethylene sample
Approximately 2 to 3 feet of head
room above flume is required.
Other dimensions depend upon size
of flume. Refrigerator case is
30"W x 24"D x 36"H.
67
-------
Figure 6. Lakeside Trebler Model T-2 Sample:
Photograph courtesy of Lakeside Equipment Corp.
68
-------
Base Price; $688 with plexiglass scoop.
$962 with timer.
Add $615 for refrigerator.
General Comments; Without timer the unit takes
30 samples per hour. For accurate
sampling the unit must operate in
conjunction with a Parshall flume
or weir. For raw sewage or in-
dustrial wastes with high settle-
able solids count a Parshall flume
is recommended. Daily inspection
and weekly cleaning is recommended
Lakeside Trebler Model T-2 Evaluation
1. Scoop is not likely to pick up any solids large enough
to clog sample line.
2. Scoop presents an obstruction over the entire depth of
flow during sampling cycle.
3. Scoop must be designed for range of flows anticipated
in conjunction with flume. This range has certain
limitations.
4. Movement of solids could interfere with scoop rotation;
abrasive wear on plexiglass scoop could be high.
5. No automatic starter; no self cleaning features.
6. Collects a sample for compositing from throughout the
entire depth of flow that is proportional to depth and
hence flow rate through the flume.
7. Will afford some capability of sampling floatables
as well as bottom solids.
8. Standard unit has no sample container. Optional
refrigerator would appear to offer reasonable
protect ion.
9. Designed for operation in the flow stream but requires
a Parshall flume for best operation which would rule
out most manholes.
10. Unit cannot withstand total immersion.
69
-------
11. Unit is not designed to operate in freezing ambients
12. Unit must be in flow stream to function.
70
-------
Designation;
Manufacturer:
Sampler Intake:
Gathering Method:
Sample Lift:
Line Size;
Sample Flow Rate
Sample Capacity:
Controls:
Power Source:
Sample Refrigerator;
Construction Materials
Basic Dimensions:
MARKLAND MODEL 1301
Markland Specialty Engineering Ltd.
Box 145
Etobicoke, Ontario (Canada
Telephone (416) 625-0930
Small gravity filled sample cham-
ber equipped with patented non-
clogging "duckbill" inlet control.
Forced flow due to pneumatic
ej ection.
Depends upon pressure available.
1/4" I.D.
Varies with pressure and lift.
Composits 75 ml aliquots into a
2-gallon bottle.
Solid state clock allows selecting
intervals between aliquots of
15-60 minutes. Optional controller
allows pacing from external flow
meter.
Compressed air bottle plus two
60-volt dry cell lantern batteries.
None
Standard intake housing is aluminum
alloy, stainless steel or PVC
available as alternates; standard
"duckbill" is EPT, Buna-N or Viton
available; Tygon tubing, stainless
steel or plastic fittings, poly-
ethylene sample bottle, fiberglass
case .
Sample intake is 2 7/8" diameter
by 5" high; case is 17"W x 12"D
x 28"H; weighs 60 pounds; portable.
71
-------
Base Price: $995; add $115 for stainless steel
or PVC intake, $20 for Viton "duck-
bill", $100 for flow proportional
adapter; all prices include air
freight and duty.
General Comments; The heart of the sampler is the
patented rubber "duckbill" in the
sample intake housing. It is
round on the bottom (about 1 1/2"
diameter) and flattens out to a
flaired top (about 3" high) where
the opening is simply a slit. When
the intake is vented to atmosphere,
the hydrostatic liquid head forces
a sample up through the vertical
inlet and through the "duckbill"
slit, which acts like a screen
(the lips can only open a limited
amount), until the pressure is
equalized. When air pressure is
applied to raise the sample the
"duckbill" lips close (acting as
a check valve), and the squeezing—
shut progresses downwards toward
the bottom inlet expelling ahead
(in a sort of milking action) any
contained solids which fall back
into the stream due to gravity.
Markland Model 1301 Evaluation
1. Sampler intake should be free from clogging; "duckbill"
will not pass any solids large enough to clog sample
line; relatively high discharge pressure (15-35 psi)
will also help prevent clogging.
2. Sampler intake presents a rigid obstruction to the flow,
3. Sampling chamber will fill immediately following dis-
charge of previous aliquot, resulting in a sample not
necessarily representative of conditions in the sewer
at the time of the next triggering signal. Represen-
tativeness is also questionable at high flow rates.
4. Movement of large objects in the flow could damage or
even physically destroy the sampler intake.
5. Has no automatic start or self- cleaning features.
72
-------
6. Collects spot samples at either preset time intervals
or paced by an external flowmeter and composits them
in a suitable container.
7. Appears unsuitable for collection of either floatable
materials or coarser bottom solids.
8. No refrigeration is provided. Cross-contamination
appears likely.
9. Unit is designed for manhole operation.
10. Cannot withstand total immersion.
11. Should be able to operate in freezing ambients for
some period of time.
12. With a fully charged gas bottle lifts in excess of
30 feet should be obtainable putting very little
restriction on operating head conditions.
73
-------
Designat ion;
Manufacturer:
Sampler Intake:
Gathering Method:
S amp1e Lift:
Line Size:
Sample Flow Rate:
Sample Capacity:
Controls:
Power Source:
Sample Refrigerator:
Construction Materials
Basic Dimensions:
MARKLAND MODEL 101
Markland Specialty Engineering Ltd.
Box 145
Etobicoke, Ontario (Canada)
Telephone (416) 625-0930
Small gravity filled sample cham-
ber equipped with patented non-
clogging "duckbill" inlet control.
Forced flow due to pneumatic
ej ection.
Depends upon pressure available.
1/4" I.D.
Varies with pressure and lift.
Composits 75 ml aliquots into a
2-gallon bottle.
A cycle timer with field adjust-
able cams allows taking an aliquot
every 10, 15, 20, 30, or 60 minutes
Plant air for Model 101; Model 2101
includes air compressor and motor;
110V ac.
6 cubic feet automatic refrigerator
to hold either a 2- or 5-gallon
bottle available.
Standard intake housing is alumi-
num alloy, stainless steel or PVC
available as alternates; standard
"duckbill" is EPT, Buna-N or Viton
available; Tygon tubing, stainless
steel or plastic fittings, poly-
ethylene sample bottle.
Sample intake is 2 7/8" diameter
by 5" high; wall mounted control
box is 6"W x 4"D x 6"H; fixed
ins tallation.
74
-------
Base Price; $540 for Model 101 including con-
trol box, remote sampling intake,
air filter, regulator and pressure
gauge, 100 feet of tubing, and
2 gallon sample collection bottle;
$580 for Model 2101 including
control box, remote sampling in-
take, air compressor and motor,
100 feet of tubing, and 2 gallon
sample collection bottle; add
$115 for stainless steel or PVC
intake, $20 for Viton "duckbill",
$325 for refrigerator, $10 for
5 gallon sample container; all
prices include air freight and
duty.
General Comments: The heart of the sampler is the
patented rubber "duckbill" in the
sample intake housing. It is round
on the bottom (about 1 1/2" diam-
eter) and flattens out to a flaired
top (about 3" high) where the open-
ing is simply a slit. When the in-
take is vented to atmosphere, the
hydrostatic liquid head forces a
sample up through the "duckbill"
slit, which acts like a screen
(the lips can only open a limited
amount), until the pressure is
equalized. When air pressure is
applied to raise the sample the
"duckbill" lips close (acting as
a check valve), and the squeezing-
shut progresses downwards toward
the bottom inlet expelling ahead
(in a sort of milking action) any
contained solids which fall back
into the stream due to gravity.
Markland Model 101 Evaluation
1. Sampler intake should be free from clogging; "duckbill"
will not pass any solids large enough to clog sample
line; relatively high discharge pressure (15-30 psi)
will also help prevent clogging.
2. Sampler intake presents a rigid obstruction to the flow,
75
-------
3. Sampling chamber will fill immediately following dis-
charge of previous aliquot, resulting in a sample not
necessarily representative of conditions in the sewer
at the time of the next triggering signal. Represen-
tativeness is also questionable at high flow rates.
4. Movement of large objects in the flow could damage or
even physically destroy the sampler intake.
5. Has no automatic start or self-cleaning features.
6. Collects spot samples at preset time intervals and
composits them in a suitable container.
7. Appears unsuitable for collection of either floatable
materials or coarser bottom solids.
8. Automatic refrigeration is available as an option.
Cross-contamination appears likely.
9. Unit is not designed for manhole operation.
10. Cannot withstand total immersion.
11. Should be able to operate in freezing ambients for
some period of time.
12. Lifts in excess of 30 feet should be obtainable putting
very little restriction on operating head conditions.
76
-------
Designation;
Manufacturer:
Sampler Intake;
Gathering Method:
Sample Lift;
Line Size:
Sample Flow Rate;
Sample Capacity;
Controls;
Power Source;
S ample Refrigerator;
Construction Materials
Basic Dimensions:
MARKLAND MODEL 1Q2
Markland Specialty Engineering Ltd.
Box 145
Etobicoke, Ontario (Canada)
Telephone (416) 625-0930
Small gravity filled sample cham-
ber equipped with patented non-
clogging "duckbill" inlet control.
Forced flow due to pneumatic
ej ection.
Depends upon pressure available.
1/4" I.D.
Varies with pressure and lift.
Composits 75 ml aliquots into a
2-gallon bottle.
A cycle timer with field adjustable
cams allows taking an aliquot every
10, 15, 20, 30, or 60 minutes.
Plant air plus 110V ac.
6 cubic foot automatic refrigerator
to hold either a 2- or 5-gallon
bottle available.
Standard intake housing is alumi-
num alloy, stainless steel or PVC
available as alternates; standard
"duckbill" is EPT, Buna-N or Viton
available; Tygon tubing, stainless
steel or plastic fittings, poly-
ethylene sample bottle, fiberglass
cas e.
Sample intake is 2 7/8" diameter
by 5" high; wall mounted control
box is 10"W x 5"D x 12"H; fixed
ins tallation.
77
-------
B ase Price: $825 including control box, remote
sampling intake, air filter, regu-
lator and pressure gauge, 100 feet
of tubing, and 2 gallon sample
collection bottle; add $115 for
stainless steel or PVC intake,
$20 for Viton "duckbill", $325 for
refrigerator, $10 for 5 gallon sam-
ple container; all prices include
air freight and duty.
General Comments: The heart of the sampler is the
patented rubber "duckbill" in the
sample intake housing. It is round
on the bottom (about 1 1/2" diam-
eter) and flattens out to a flaired
top (about 3" high) where the open-
ing is simply a slit. When the in-
take is vented to atmosphere, the
hydrostatic liquid head forces a
sample up through the vertical in-
let and through the "duckbill"
slit, which acts like a screen
(the lips can only open a limited
amount), until the pressure is
equalized. When air pressure is
applied to raise the sample the
"duckbill" lips close (acting as a
check valve), and the squeezing-
shut progresses downwards toward
the bottom inlet expelling ahead
(in a sort of milking action) any
contained solids which fall back
into the stream due to gravity.
The control box has a pinch valve
on the sample line which squeezes
it closed and keeps the sample in-
take housing filled with pressur-
ized air between aliquot ejections.
This feature is useful when sam-
pling liquids with high solids con-
tent which would tend to settle out
in the intake while waiting to be
ejected. Also, the air pressuriza-
tion provides a reverse air purge
back through the "duckbill" thereby
prividing a sort of self cleaning
action should any solids build up
in the "duckbill" inlet. The manu-
facturer recommends this model in
78
-------
particular for raw sewage or
liquids with solids content over
200 PPM.
Markland Model 102 Evaluation
1. Sampler intake sould be free from clogging; "duckbill"
will not pass any solids large enough to clog sample
line; relatively high discharge pressure (15-35 psi)
will also help prevent clogging.
2. Sampler intake presents a rigid obstruction to the flow
3. Representativeness of sample is questionable at high
flow rates.
4. Movement of large objects in the flow could damage or
even physically destroy the sampler intake.
5. Has no automatic starter. Reverse air purge through
"duckbill" provides a sort of self-cleaning action.
6. Collects spou samples at preset time intervals and
composits them in a suitable container.
7. Appears unsuitable for collection of either floatable
materials or coarser bottom solids.
8. Automatic refrigeration is available as an option.
Cross-contamination appears likely.
9. Unit is not designed for manhole operation.
10. Cannot withstand total immersion.
11. Should be able to operate in freezing ambients for
some period of time.
12. Lifts in excess of 30 feet should be obtainable putting
very little restriction on operating head conditions.
79
-------
Designation;
Manufacturer:
Sampler Intake;
Gathering Method
S ample Lift:
Line Size:
Sample Flow Rate:
Sample Capacity:
ControIs:
P ower Source:
Sample Refrigerator:
Construction Materials
Basic Dimensions:
MARKLAND MODEL 104T
Markland Specialty Engineering Ltd.
Box 145
Etobicoke, Ontario (Canada)
Telephone (416) 625-0930
Small gravity filled sample cham-
ber equipped with patented non-
clogging "duckbill" inlet control.
Forced flow due to pneumatic
ej ection.
Depends upon pressure available.
1/4" I.D.
Varies with pressure and lift.
Composits 75 ml aliquots into a
2-gallon bottle.
Solid state predetermining digital
counter accepts signals from an
external flowmeter to gather sam-
ples proportional to flow. Op-
tional solid state clock allows
sampling at predetermined time
intervals .
Plant air for Model 104T;
Model 2104T includes air compressor
and motor; 110V ac.
6 cubic foot automatic refrigerator
to hold either a 2- or 5-gallon
bottle available.
Standard intake housing is alumi-
num alloy, stainless steel or PVC
available as alternates; standard
"duckbill" is EPT, Buna-N or Viton
available; Tygon tubing, stainless
steel or plastic fittings, poly-
ethylene sample bottle, fiberglass
cas e .
Sample intake is 2 7/8" diameter
by 5" high; fixed installation.
80
-------
lase Price; $975 for Model 104T including con-
trol box, remote sampling intake,
air filter, regulator and pressure
gauge, 100 feet of tubing, and
2 gallon sample collection bottle;
$1,005 for Model 2104T including
control box, remote sampling in-
take, air compressor and motor,
100 feet of tubing, and 2 gallon
sample collection bottle; add
$115 for stainless steel or PVC
intake, $20 for Viton "duckbill",
$325 for refrigerator, $10 for
5 gallon sample container, $195
for plug-in solid state clock
module; all prices include air
freight and duty.
General Comments: The heart of the sampler is the
patented rubber "duckbill" in the
sample intake housing. It is round
on the bottom (about 1 1/2" diam-
eter) and flattens out to a flaired
top (about 3" high) where the open-
ing is simply a slit. When the in-
take is vented to atmosphere, the
hydrostatic liquid head forces a
sample up through the vertical in-
let and through the "duckbill" slit,
which acts like a screen (the lips
can only open a limited amount),
until the pressure is equalized.
When air pressure is applied to
raise the sample the "duckbill"
lips close (acting as a check
valve), and the squeezing-shut
progresses downwards toward the
bottom inlet expelling ahead (in
a sort of milking action) any con-
tained solids which fall back into
the stream due to gravity. The two
digit counter, when connected to an
external flowmeter providing dry
contact pulsing closed momentarily
with frequency proportional to flow,
counts down from the preset point
to zero. When zero is reached, the
sampling circuit latches in and
extracts an aliquot while simul-
taneously resetting the counter
81
-------
back to the reset point. Pulses
received while the aliquot is being
ejected are counted without loss.
Markland Model 104T Evaluation
1. Sampler intake should be free from clogging; "duckbill"
will not pass any solids large enough to clog sample
line; relatively high discharge pressure (15-35 psi)
will also help prevent clogging.
2. Sampler intake presents a rigid obstruction to the flow
3. Sampling chamber will fill immediately following dis-
charge of previous aliquot, resulting in a sample not
necessarily representative of conditions in the sewer
at the time of the next triggering signal. Represen-
tativeness is also questionable at high flow rates.
4. Movement of large objects in the flow could damage
or even physically destroy the sampler intake.
5. Has no automatic start or self-cleaning features.
6. Collects spot samples at either preset time intervals
with clock option or paced by an external flowmeter and
composits them in a suitable container.
7. Appears unsuitable for collection of either floatable
materials or coarser bottom solids.
8. Automatic refrigeration is available as an option.
Cross-contamination appears likely.
9. Unit is not designed for manhole operation.
10. Cannot withstand total immersion.
11. Should be able to operate in freezing ambients for
some period of time.
12. Lifts in excess of 30 feet should be obtainable putting
very little restriction on operating head conditions.
82
-------
Designation;
Manufacturer:
Sampler Intake;
Gathering Method
Sample Lift:
Line Size:
Sample Flow Rate
Sample Capacity;
Controls:
Power Source:
Sample Refrigerator;
Construction Materials
Basic Dimensions;
Base Price;
General Comments:
N-CON SURVEYOR MODEL
N-Con Systems Company, Inc.
308 Main Street
New Rochelle, New York 10801
Phone (914) 235-1020
End of 1/2 inch sampling tube
installed to suit by user.
Suction lift by self-priming
centrifugal pump.
6 feet maximum.
1/4" I.D. line connects diverter to
sample container.
5 gpm.
Aliquot size adjustable from
approximately 150 ml to 5000 ml;
composited in user supplied con-
tainer (2 1/2-gallon jug to
55-gallon drum).
Timer may be set to collect from
2 to 30 samples per hour; may also
be paced by signals from external
flow meter.
115V ac or 12V dc for timer opera-
tion only (user supplies batteries).
None
Sampling train is PVC, nylon, epoxy
resin, and Buna-N.
Very small portable unit. User
provided sample container will be
largest component.
$275.
When sample is to be collected, the
self-priming pump operates for a
preset period of time which deter-
mines the volume of the sample.
83
-------
Approximately 15 percent of the
pump's throughput is diverted to
the sample receiver by a fluidic
diverter. When the pump stops the
fall of liquid level in the exhaust
line backwashes to help prevent
clogging.
N-Con Surveyor Model Evaluation
1. Unit would not appear to be vulnerable to clogging.
2. Will depend upon way user mounts end of sampling tube.
3. Should operate reasonably well under all flow
conditions.
4. Movement of solids should not hamper operation.
5. No automatic starter. Fall of liquid in exhaust line
when pump stops will backwash giving a sort of self
cleaning action.
6. Can collect either timer or flow meter paced samples
and composite them in a suitable container. Repre-
sentativeness of sample will depend upon user mounting
of intake tube.
7. Unsuitable for collection of samples of floatables and
coarser bottom solids without specially designed
intake by user.
8. No refrigeration, no sample protection. Small amount
of cross contamination might be experienced.
9. Should be able to operate in manhole enviroment.
10. Cannot withstand immersion.
11. Not ideally suited for operation in freezing ambients.
12. Maximum lift of 6 feet limits location of unit.
84
-------
Designation;
Manufacturer:
Sampler Intake;
Gathering Method
S amp 1e Lift;
Line Size:
Sample Flow Rate:
Sample Capacity;
Controls;
Power Source:
Sample Refrigerator;
Construction Materials
Basic Dimensions:
Base Price;
General Comments:
N-CON SCOUT MODEL
N-Con Systems Company, Inc.
308 Main Street
New Rochelle, New York 10801
Phone (914) 235-1020
Plastic strainer approximately
2" diameter x 8" long and perfo-
rated with 1/8" holes.
Suction lift by peristaltic pump.
Up to 15 feet.
1/4" I.D.
150 ml per minute.
Aliquot size is adjustable via a
solid state timer to suit hydrau-
lics of installation and sampling
programs; composited in a 1-gallon
container.
24-hour key wound clock turns
programmer drum which can be set to
collect 1 to 8 samples per hour.
12V dc dry cell battery.
None
Sampling train PVC, silicon
rubber, polyethylene; case is
compression molded fiberglass.
14"W x 6"D x 17"H; weighs
22 pounds empty.
$450.
On signal, pump starts and runs in
reverse to clear pump and tubing of
previous sample, then runs forward
to deliver sample to container.
Case is weatherproof.
85
-------
N-Con Scout Model Evaluation
1. Peristaltic action of pump should reduce probability
of clogging.
2. Obstruction of flow will depend upon way user mounts
intake.
3. Should operate reasonably well under all flow condi-
tions, but fairly low intake velocity could affect
representativeness of sample at high flow rates.
4. Movement of solids should not hamper operation.
5. No automatic starter. At start of each cycle pump
operates in reverse to clear line of previous sample
to help minimize cross contamination and offer a sort
of self cleaning.
6. Unit collects samples at preset time intervals and
composits them in container. Representativeness of
sample will depend upon user mounting of intake tube.
7. Unit does not appear suitable for collecting floatables
or coarser bottom solids.
8. No refrigeration. Reasonably good sample protection
(container is connected only to pump). Cross con-
tamination should be small.
9. Designed to operate in manhole environment.
10. Cannot withstand total immersion.
11. Not suited for operation in freezing ambients.
12. Maximum lift of 15 feet places some restriction on use
of unit.
86
-------
Designation:
Manufacturer:
Sampler Intake:
Gathering Method
S amp1e Lift:
Line Size:
Sample Flow Rate
Sample Capacity:
Controls :
Power Source;
Sample Refrigerator;
Construction Materials
Basic Dimensions;
Base Price;
General Comments:
N-CON SENTRY MODEL
N-Con Systems Company, Inc.
308 Main Street
New Rochelle, New York 10801
Phone (914) 235-1020
Plastic strainer approximately
2" diameter x 8" long and perfo-
rated with 1/8" holes.
Suction lift by peristaltic pump.
Up to 15 feet.
1/4" I.D.
150 ml per minute.
Collects 24 discrete 250 ml samples
made up of from 2 to 8 individual
aliquots over a period of 3, 6, 8,
12, or 24 hours.
Same as Scout Model.
12V dc dry cell battery standard,
optional 115V ac converter.
None
Same as Scout, but glass sample
j ars .
16"W x 14"D x 13"H; weighs
35 pounds empty.
$895.
Similar in operation to the Scout
Model except for capability to
collect discrete samples. Sampler
automatically shuts off after
24th bottle is filled.
87
-------
06
00
¥
Figure 7. N-Con Sentry Model Sampler
Photograph courtesy of N-Con Systems Co., Inc.
-------
N-Con Sentry Model Evaluation
1. Peristaltic action of pump should reduce probability
of clogging.
2. Obstruction of flow will depend upon way user mounts
intake.
3. Should operate reasonably well under all flow condi-
tions, but fairly low intake velocity could affect
representativeness of sample at high flow rates.
4. Movement of solids should not hamper operation.
5. No automatic starter. At start of each cycle pump
operates in reverse to clear line of previous sample
to help minimize cross contamination and offer a sort
of self cleaning.
6. Unit collects 24 discrete samples made up of 2 to
8 individual aliquots at preset time intervals. Repre-
sentativeness of sample will depend upon user mounting
of intake tube.
7. Uni.t does not appear suitable for collection of
floatables or coarser bottom solids.
8. No refrigeration. Reasonably good sample protection.
Cross contamination should be small.
9. Designed to operate in manhole environment.
10. Cannot withstand total immersion.
11. Not suited for operation in freezing ambients.
12. Maximum lift of 15 feet places some restriction on
use of unit.
89
-------
Designation:
Manufacturer:
Sampler Intake:
Gathering Method
Sample Lift:
Line Size:
Sample Flow Rate
Sample Capacity:
Controls:
Power Source:
Sample Refrigerator
Construction Materials
Basic Dimensions:
Base Price:
N-CON TREBLER MODEL
N-Con Systems Company, Inc.
308 Main Street
New Rochelle, New York 10801
Phone (914) 235-1020
Specially designed scoop.
Mechanical; oscillating scoop is
lowered into the channel traversing
entire depth of flow, then returned
to its raised position, draining
the collected sample by gravity
through a swivel fitting coaxial
with the hub into a sample
container.
Unit must be in flow stream.
1/2" I.D. pipe connects hub to
sample container.
Not applicable.
Scoop is shaped to gather a volume
of liquid that is proportional to
the channel flow; can vary typi-
cally from 200 to 600 ml when
installed in a Parshall flume.
Electric timer may be set to take
from 3 to 20 samples per hour.
115V ac
Automatic refrigerator available
which provides 4° to 10°C sample
storage.
Cast aluminum frame and cover;
PVC scoop, plastic pipe.
Approximately 2 to 3 feet of head-
room is required. Other dimensions
depend upon size of flume or weir.
Refrigerator case is 24"W x 26"D
x 30"H.
$995; add $565 for refrigerator.
90
-------
General Comments; Drive mechanism and control pro-
grammer are totally enclosed and
weatherproof, with no exposed
chains or sprockets. Oscillating
action of scoop permits installa-
tion in smaller weir boxes and man-
holes and lessens the chances of
fouling with rags, etc., or being
damaged by floating debris. Must
operate in conjunction with a weir
or Parshall flume.
N-Con Trebler Model Evaluation
1. Scoop is not likely to pick up any solids large enough
to clog sample line.
2. Scoop presents an obstruction over the entire depth of
flow during sampling cycle.
3. Scoop must be designed for range of flows anticipated
in conjunction with flume. This range has certain
limitations.
4. Movement of solids could interfere with scoop rotation;
abrasive wear on rigid, high impact PVC scoop should
not be too great.
5. No automatic starter; no self cleaning features.
6. Collects a sample for compositing from throughout the
entire depth of flow that is proportional to depth and
hence flow rate through the flume.
7. Will afford some capability of sampling floatables as
well as bottom solids.
8. Standard unit has no sample container. Optional
refrigerator would appear to offer reasonable
protection.
9- Designed for operation in the flow stream, but requires
a Parshall flume for best operation which would rule
out most manholes.
10. Unit cannot withstand total immersion.
11. Unit is not designed to operate in freezing ambients.
12. Unit must be in flow stream to function.
91
-------
Designation:
Manufacturer:
Sampler Intake;
Gathering Method:
Sample Lift;
Line Size:
Sample Flow Rate
Sample Capacity;
Controls:
Power Source:
Sample Refrigerator:
N-CON SENTINEL MODEL
N-Con Systems Company, Inc.
308 Main Street
New Rochelle, New York 10801
Phone (914) 235-1020
Provided by user; sampler has
standard 2" pipe inlet.
External head to provide flow
through a sampling chamber from
which an oscillating dipper (after
McGuire and Stormguard) extracts
a sample aliquot and transfers it
to a funnel where it is gravity
fed to a composite bottle.
Not applicable.
Smallest line in sampling train is
the one connecting the funnel to
the sample bottle; it appears to
be about 1 inch.
10 to 50 gpm.
Sampling dipper collects a 25 ml
sample; a 2 gallon composite con-
tainer is provided.
Constant rate sampling (between 3
and 20 samples per hour) is con-
trolled by built-in timer; flow
proportional composits are col-
lected by connecting to the elec-
trical output of a pulse duration
or integrating external flow meter.
115V ac
Automatic refrigerator to maintain
sample at 4° to 10°C is available.
Construction Materials: PVC and polyethylene.
Basic Dimensions:
22"W x 28"D x 58"H. Designed for
fixed installation. Weighs
185 pounds.
92
-------
Base Price: $2,350 with refrigerator.
General Comments: Manufacturer claims representative
samples assured due to design of
sample chamber which causes
thorough mixing of liquid before
it flows over adjustable weir.
N-Con Sentinel Model Evaluation
1. Should be free from clogging. Sampling intake must be
designed by user.
2. Sampler itself offers no flow obstruction.
3. Should operate well over entire range of flow
conditions.
4. Movement of solids should not hamper operation.
5. Designed for continuous operation; no automatic
starter. Continuous flow serves a self cleaning
function and should minimize cross contamination.
6. Can collect either flow proportional or fixed time
interval composites. Representativeness of sample
will be a function of sample intake which is not a
part of this unit.
7. Collection of floatables and coarser bottom solids
will depend upon design of sampling intake.
8. Automatic refrigeration maintains samples at 44° to
10°C. Offers good sample protection and freedom from
precontamination.
9. Not designed for confined space or manhole operation.
10. Cannot withstand total immersion.
11. Does not appear capable of prolonged exposure to
extremely cold ambient conditions.
12. Operating head is provided by user.
93
-------
Designation:
Manufacturer :
Sampler Intake;
Gathering Method:
Sample Lift;
Line Size:
Sample Flow Rate:
Sample Capacity:
Controls:
Power Source:
Sample Refrigerator;
Construction Materials
Basic Dimensions:
Base Price:
PHIPPS AND BIRD DIPPER-TYPE^
Phipps and Bird, Inc.
303 South 6th Street
Richmond, Virginia 23205
Phone (703) 644-5401
Dipping bucket.
Mechanical; dipper on sprocket-
chain drive.
Up to 10 feet standard, longer on
special order-
Not applicable.
Not applicable.
Dipping bucket holds 200 ml; user
supplies sample composite container
to suit.
Sampling cycle can either be
started at fixed, selected inter-
vals from a built-in timer
(15 minutes) or in response to
signals from an external inte-
grating flow meter.
115V ac or 12V dc
None
Dipper and funnel are stainless
steel; sprockets and chain are
steel (stainless available),
supports are angle iron.
Base is 16" x 24" and will pass
through a 30" diameter opening,
unit extends 3' above base. Fixed
installation.
$725; $1,145 in stainless steel;
$1,980 for explosion proof version;
$2,450 for explosion proof version
in stainless steel.
94
-------
Figure 8. PhippB and-Bird Dipper-Type Sampler
Photograph courtesy of Phipps and Bird,
-------
General Comments: Manufacturer states unit was
designed to sample trash laden
streams where it is not possible
to operate a pump. A circuit
breaker prevents damage if unit
becomes jammed.
Phipps and Bird Dipper-Type Evaluation
1. Clogging of sampling train is unlikely; however, the
exposed chain-sprocket drive is vulnerable to jamming
by rags, debris, etc.
2. Unit provides a rigid obstruction to flow.
3. Unit should operate over full range of flows.
4. Movement of solids could jam unit.
5. No automatic starter; no self cleaning features.
6. Collects fixed size aliquots paced by built-in timer
or external flow meter and composits them in a
suitable container.
7. Does not appear well suited for collecting either
floatables or coarser bottom solids.
8. No sample collector provided.
9. Unit is capable of manhole operation.
10. Unit is not weatherproof; cannot withstand total
immersion.
11. Unit is not suitable for prolonged operation in
freezing ambients.
12. Unit would appear impractical for very long lifts (say
ab ove 60 feet) .
96
-------
Designation;
Manufacturer:
Sampler Intake
Gathering Method
Sample Lift:
Line Size:
Sample Flow Rate;
Sample Capacity;
Controls:
Power Source:
PROTECH MODEL CG-125
Protech, Inc.
Roberts Lane
Malvern, Pennsylvania
Phone (215) 644-3854
19355
Plastic sampling chamber (about
2" diameter) with two rows of
1/8" diameter ports around the
circumference. Weighted bottom
caps are available to keep the
intake screen off the bottom.
Forced flow due to pneumatic
ej ect ion.
Standard maximum is 32 feet.
1/4" O.D.
Less than 1/2 gpm; depends upon
pressure setting and lift.
Sample chamber volumes of 25, 50,
75 or 100 ml; sample composited in
suitable container, 1 1/2-gallon
jug available.
Sampling frequency is determined
by metering gas pressure (via a
rotometer with a vernier needle
valve and two float balls) into a
surge tank until a preset pressure
(normally 15 psi) is reached,
whereupon a pressure controller
releases the gas (a 2 psi differ-
ential) to the sample chamber
forcing the sample up to the sample
bottle and blowing the lines clear.
The higher the gas flow rate the
higher the sampling frequency.
Sampling frequency is adjustable
from 30 seconds to over 30 minutes.
Three 1-pound cans of refrigerant
on a common manifold inside the
case is standard; compressed air or
nitrogen can also be used.
97
-------
Sample Refrigerator;
Construction Materials
Basic Dimensions:
Base Price:
General Comments:
None in portable model. Stationary
models have automatic refrigerated
sample compartments.
All components in sampling train
are TFE resins, PVC, and nylon.
Case is aluminum, gas valves and
fittings are of brass and copper.
11"W x 9"D x 15"H standard;
18" deep case large enough to hold
a 1 1/2 gallon sample container
and winterizing kit is available
for portable models.
$583 for basic unit including
50 ml sample chamber, 6 cans of
refrigerant, and two 20-foot lengths
of tubing. Add $60 for deep case;
$140 for winterizing kit; $10 for
100 ml sample chamber. CG-125S is
version in upright cabinet for
fixed indoor station operation with
refrigerated sample storage at
$1,650; in outdoor, weatherproof
winterized cabinet price is $2,310.
Portable model is explosion proof,
no battery or electrical power is
required. Manufacturer claims unit
will sample up to 1/8" diameter
solids. Check valve in sample
chamber is self-cleaning. Self-
cleaning feature is accomplished by
the two-way flushing action which
occurs during each filling and
pressurizing cycle. A flow
splitter provides 1 to 2, 1 to 1,
or 2 to 1 ratio of sample flow to
waste return flow- Three cans of
refrigerant will operate the sam-
pler from 3 to 5 days in continuous
operation. Winterizing is accom-
plished using strip heaters oper-
ated by an automatic temperature
control. Case dimensions of sta-
tionary models are 29 1/2"W
x 25 1/2"D x 48"H on 12" legs.
98
-------
Protech Model CG-125 '^aluation
1. Sampling train is unobstructed 1/4" O.D. passageway
which will pass small solids. No pump to clog.
2. Sampling chamber normally rests on a weighted cap on
sewer invert. Unless clamped in place, it offers no
rigid obstruction to flow-
3. Sampling chamber will fill immediately following dis-
charge of previous aliquot. Circulation of flow
through chamber would appear to be limited, resulting
in a sample not necessarily representative of condi-
tions in the sewer at the time of the next triggering
signal. Representativeness is also questionable at
high flow rates .
4. Movement of solids in flow could affect position of
sampling chamber and erode plastic lines if flow is
deep enough.
5. No automatic starter. A self-cleaning feature of sorts
in the sampling chamber is accomplished by the two-way
flushing action which occurs during each filling and
pressurizing cycle.
6. Collects spot samples at preset time intervals and
composits them in a suitable container.
7. Appears unsuitable for collection of either floatable
materials or coarser bottom solids.
8. No refrigeration available in the portable version.
Stationary units have automatic, refrigerated sample
compartments. Cross contamination appears likely.
9. Portable unit is designed for manhole operation.
10. Case is weatherproof but will not withstand total
immersion.
11. Can operate in freezing ambients if fitted with
optional winterizing kit.
12. Upper lift limit of 32 feet does not pose a great
restriction on operating head conditions.
99
-------
Designation:
Manufacturer:
Sampler Intake
Gathering Method:
Sample Lift:
Line Size:
Sample Flow Rate
Sample Capacity:
Controls:
PROTECH MODEL CG-125FP
P rotech, Inc.
Roberts Lane
Malvern, Pennsylvania
Phone (215) 644-3854
19355
in
Plastic sampling chamber (about
2" diameter) with two rows of
1/8" diameter ports around the
circumference. Weighted bottom
caps are available to keep the
intake screen off the bottom.
Forced flow due to pneumatic
ej ection.
Standard maximum is 32 feet.
1/4" O.D.
Less than 1/2 gpm; depends upon
pressure setting and lift.
Sample chamber volumes of 25, 50,
75 or 100 ml; sample composited i
suitable container, 1 1/2-gallon
jug available.
Can take samples at preset time
intervals in same way as
Model CG-125. For flow propor-
tional sampling a normally closed,
solenoid operated valve in the gas
inlet opens momentarily on receiv-
ing an impulse from an external
flow registering device. The sam-
pling frequency is determined by
the frequency and duration of these
impulses and the rotometer setting.
Thus the intermittent flow signal
impulses are translated into fluidic
impulses that are accumulated in
the surge tank which serves as a
totalizer. If the flow proportional
signal is supplied by a totalizer
and it is desired to take one sam-
ple per impulse, a solid state timer
is available which will hold the
solenoid open long enough to accu-
mulate the necessary pressure.
100
-------
Power Source:
Sample Refrigerator:
Construction Materials
Basic Dimensions:
Basic Price:
General Comments:
115V ac or 6V dc; three 1-pound
'~:ans of refrigerant on a common
manifold inside the case is
standard; compressed air or
nitrogen can also be used.
None
All components in sampling train
are TFE resins, PVC, and nylon.
Case is aluminum, gas valves and
fittings are of brass and copper.
11"W x 9"D x 15"H standard.
18" deep case large enough to hold
a 1 1/2 gallon sample container
and winterizing kit is available.
Portable.
$693 for basic unit including
50 ml sample chamber, 6 cans of
refrigerant, and two 20-foot lengths
tubing. Add $60 for deep case;
$140 for winterizing kit; $10 for
100 ml sample chamber; $205 for
solid state timer.
Basically a flow proportional
version of Model CG-125. Com-
pletely portable in battery
version. Control solenoid is
certified by UL for use in hazard-
ous areas.
Protech Model CG-125FP Evaluation
1. Sampling train is unobstructed 1/4" O.D. passageway
which will pass small solids. No pump to clog,
2. Sampling chamber normally rests on weighted cap on
sewer invert. Unless clamped in place, it offers no
rigid obstruction to flow.
3. Sampling chamber will fill immediately following dis-
charge of previous aliquot. Circulation of flow
through chamber would appear to be limited, resulting
in a sample not necessarily representative of condi-
tions in the sewer at the time of the next triggering
signal. Representativeness is also questionable at
high flow rates .
101
-------
4. Movement of solids in flow could affect position of
sampling chamber and erode plastic lines if flow is
deep enough.
5. No automatic starter. A self cleaning feature of sorts
in the sampling chamber is accomplished by the two-way
flushing action which occurs during each filling and
pressurizing cycle.
6. Collects spot samples at either preset time intervals
or paced by an external flow meter and composits them
in a suitable container.
7. Appears unsuitable for collection of either floatable
materials or coarser bottom solids.
8. No refrigeration available. Cross contamination
appears likely.
9. Unit is designed for manhole operation.
10. Case is weatherproof but will not withstand total
immersion.
11. Can operate in freezing ambients if fitted with
optional winterizing kit.
12. Upper lift limit of 32 feet does not pose a great
restriction on operating head conditions.
102
-------
Designation
Manufacturer:
Sampler Intake:
Gathering Method
Sample Lift;
Line Size;
Sample Flow Rate:
Sample Capacity:
Controls:
Power Source:
PROTECH MODEL CG-150
Protech, Inc.
Roberts Lane
Malvern, Pennsylvania
Phone (215) 644-3854
19355
Plastic sampling chamber (about
2" diameter) with two rows of
1/8" diameter ports around the
circumference. Weighted bottom
caps are available to keep the
intake screen off the bottom.
Forced flow due to pneumatic
ej ection.
Standard maximum is 32 feet.
1/4" O.D.
Less than 1/2 gpm; depends upon
pressure setting and lift.
Sample chamber volumes of 25, 50,
75 or 100 ml; sample composited in
suitable container, 1 1/2-gallon
jug available.
Clock timer mode: Adjustable cams
turned by a 7-day spring-wound
clock actuate a valve in the com-
pressed gas supply line to control
sampling for an adjustable time
period once every hour or every
8 hours over a 24 hour or 7 day
period. Adjustable time-off, time-
on plus automatic start-stop opera-
tion is a standard feature.
Flow proportional mode: Same basic
principle as Model CG-125FP.
Three 1-pound cans of refrigerant
on a common manifold inside the
case is standard; compressed air or
nitrogen can also be used. Port-
able version uses 6V battery; sta-
tionary models use 115V ac.
103
-------
Sample Refrigerator:
Construction Materials
Basic Dimensions:
Base Price:
General Comments:
None in portable models. Station-
ary models have automatic refrig-
erated sample compartments.
All components in sampling train
are TFE resins, PVC, and nylon.
Case is aluminum, gas valves and
fittings are of brass and copper.
Portable - 11"W x
Stationary - 27"W
x 49 1/2"H.
18"D
25
x
x 15"H.
1/2"D
$895 for basic portable unit in-
cluding 50 ml sampling chamber,
6 cans of refrigerant, deep case,
and two 20-foot lengths of tubing.
Stationary unit is $1,850 in in-
door cabinet and $2,510 in weather'
proof outdoor cabinet.
Similar to Model CG-125FP with
addition of 7-day clock and auto-
matic start-stop.
Protech Model CG-150 Evaluation
1. Sampling train is unobstructed
which will pass small solids.
1/4" O.D. passageway
No pump to clog.
Sampling chamber normally rests on weighted cap on
sewer invert. Unless clamped in place, it offers no
rigid obstruction to flow.
Sampling chamber will fill immediately following dis-
charge of previous aliquot. Circulation of flow
through chamber would appear to be limited, resulting
in a sample not necessarily representative of condi-
tions in the sewer at the time of the next triggering
signal. Representativeness is also questionable at
high flow rates .
Movement of solids in flow could affect position of
sampling chamber and erode plastic lines if flow is
deep enough.
Has automatic start-stop. A self cleaning feature of
sorts in the sampling chamber is accomplished by the
104
-------
two-way flushing action which occurs during each
filling and pressurizing cycle.
6. Collects spot samples at either preset timer intervals
or paced by an external flow meter and composits them
in a suitable container.
7. Appears unsuitable for collection of either floatable
materials or coarser bottom solids.
8. No refrigeration in portable version; stationary units
have automatic refrigerated sample compartments. Cross
contamination appears likely.
9. Portable unit is designed for manhole operation.
10. Case is weatherproof but will not withstand total
immersion.
11. Can operate in freezing ambients if fitted with
optional winterizing kit.
12. Upper lift limit of 32 feet does not pose a great
restriction on operating head conditions.
105
-------
Designation;
Manufacturer:
Sampler Intake;
Gathering Method
S amp 1e Lift;
Line Size;
Sample Flow Rate
Sample Capacity:
Controls:
PROTECH MODEL CEL-300
Protech, Inc.
Roberts Lane
Malvern, Pennsylvania
Phone (215) 644-3854
19355
Power S ource:
Plastic cylindrical (about
4" diameter x 8" long) screen
perforated with 1/8" diameter
ports over pump inlet.
Forced flow from submersible pump.
Standard maximum is 32 feet.
1/2" I.D. inlet hose.
1 to 2 gpm recommended.
Aliquot volume is a function of the
preset diversion time; 1 1/2 gallon
composite container is standard.
Unit operates on continuous-flow
principle, returning the uncol-
lected sample to waste. Sample
is pumped through a non-clogging
flow-diverter type chamber. Upon
receiving a signal from either an
external flow registering device
or the built-in timer, the unit
diverts the flow for a preset
period of time (adjustable from
0.06 to 1.0 second) to the sample
container. When operating in the
timed sampling mode, the sampling
frequency can be set for 1, 2, or
5 minutes. When operating in the
flow-proportional mode the sampler
may accept either a timed pulse
signal which can be accumulated
(totalized) by the built-in timer,
or a single totalized signal where-
upon the sampler will be fired
directly.
115V ac
106
-------
Sample Refrigerator;
Construction Materials
Basic Dimensions:
Base Price:
General Comments:
None in portable model. Stationary
models have automatic refrigerated
sample compartment.
Sampling train is PVC, nylon, stain-
less steel, and TFE resins; case is
aluminum.
Portable - 11"W x 18"D x 15"H.
Stationary - 27"W x 25 1/2"D
x 49 1/2"H.
$1,450 including 36' of 1/2" I.D.
inlet hose, 20' of 1" I.D. waste
return hose, clamps, submersible
pump and motor. Stationary model
is $2,250 in indoor cabinet and
$2,910 in weatherproof, winterized
outdoor cabinet.
Orbital magnetic drive submersible
pump is impeller type, seal-less,
epoxy-clad hermetically sealed.
For applications where sample lift
is relatively low and high pump
output is unnecessary a by-pass kit
is available to reduce flow through
diverter chamber to 1 to 2 gpm.
A Model CEG-200 which has timing
similar to CEL-300 but sample taken
with pressure operated submersible
chamber as in Model CG-125 but re-
quiring external pressure source is
available at $1,350 in portable
version, $1,950 in stationary in-
door case, and $2,610 in outdoor
winterized case.
Protech Model CEL-300 Evaluation
1. Large sampling screen chamber over pump inlet can
tolerate blockage of a number of ports and still
function. Pump and tubing should be free from
clogging.
2. Submersible pump and screen present an obstruction
to the flow.
107
-------
3. Should be capable of operation over the full range of
flow conditions.
4. Movement of small solids should not affect operation;
large objects could damage (or even physically destroy)
the in-water portion unless special protection is
provided by user.
5. No automatic starter since designed for continuous
flow. Continuous flow serves a self cleaning function
of all except line from diverter to sample bottle.
6. Collects spot samples paced either by built-in timer
or external flow meter and composits them in a
suitable container.
7. Appears unsuitable for collection of either floatable
materials or coarser bottom solids.
8. No refrigeration available in portable version.
Stationary units have automatic refrigerated sample
compartment. Cross contamination should not be too
great.
9. Portable unit is designed for manhole operation.
10. Cannot withstand total immersion.
11. Can operate in freezing ambients if fitted with
optional winterizing kit.
12. Upper lift limit of 32 feet does not pose a great
restriction on operating head conditions.
108
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Designation;
Manufacturer:
Sampler Intake;
Gathering Method
Sample Lift;
Line Size;
Sample Flow Rate
Sample Capacity;
Controls:
Power Source:
Sample Refrigerator;
Construction Materials
Basic Dimensions
Base Price:
General Comments
PROTECH MODEL DEL-240S
P rotech, Inc .
Roberts Lane
Malvern, Pennsyvlania
Phone (215) 644-3854
19355
Plastic cylindrical (about
4" diameter x 8" long) screen
perforated with 1/8" diameter
ports over pump inlet.
Forced flow from submersible pump
Standard maximum is 32 feet.
1/2" I.D. inlet hose.
1 to 2 gpm recommended.
Aliquot volume is function of pre-
set diversion time; can take
24 individual samples of 100 ml
each or one composite sample of
1 1/2-gallons.
Similar to Model CEL-300 with
addition of 7-day clock allowing
sampling at 30 minute intervals
and time-on, time-off programming.
115V ac
Automatic refrigerated sample
compartment .
Sampling train is PVC, nylon,
stainless steel, and TFE resins;
case is aluminum.
30"W x 32"D x 60"H on 12" legs;
s tat ionary .
$5,606.
Unit is basically a CEL-300S in
outdoor case with provisions for
collecting 24 discrete samples as
well as a composite sample.
109
-------
Figure 9. Protech Model DEL-240S Sampler
Photograph courtesy of Protech, Inc.
110
-------
Protech Model DEL-240S Evaluation
1. Large sampling screen chamber over pump inlet can
tolerate blockage of a number of ports and still
function. Pump and tubing should be free from
clogging.
2. Submersible pump and screen present an obstruction to
the flow.
3. Should be capable of operation over the full range of
flow conditions.
4. Movement of small solids should not affect operation;
large objects could damage (or even physically destroy)
the in-water portion unless special protection is
provided by user.
5. 7-day clock can provide programmed automatic start-
stop. Continuous flow serves a self cleaning function
of all except line from diverter to sample bottle.
6. Collects spot samples paced either by built-in timer
or external flow meter and either composits them in a
suitable container or collects them discretely in
24 individual containers.
7. Appears unsuitable for collection of either floatable
materials or coarser bottom solids.
8. Automatic refrigerated sample compartment. Cross
contamination should not be too great.
9. Unit is not designed for manhole operation.
10. Cannot withstand total immersion.
11. Can operate in freezing ambients.
12. Upper lift limit of 32 feet does not pose a great
restriction on operating head conditions.
Ill
-------
Designation;
Manufacturer:
Sampler Intake:
Gathering Method
Sample Lift;
Line Size:
Sample Flow Rate
Sample Capacity;
Controls:
Power Source:
Sample Refrigerator:
Construction Materials
Basic Dimensions:
Base Price:
QCEC MODEL CVE
Quality Control Equipment Company
6139 Fleur Drive
Des Moines, Iowa 50315
Phone (515) 285-3091
End of suction line installed to
suit by user.
Suction lift from vacuum pump.
20 foot maximum.
1/4" I.D.
Depends upon lift.
Adjustable aliquots of from 20 to
50 ml are composited in a 1/2-gal-
Ion j ug.
Sampling cycles can either be
started at fixed, selected inter-
vals by a built-in timer or in
response to signals from an ex-
ternal flow meter.
115V ac standard; 12V dc optional,
Standard model has insulated case
with built-in ice chamber; auto-
matic refrigeration is available
as an option.
Sampling train is tygon, polypro-
pylene, polyethylene, and glass;
case is fiberglass.
15"W x 15"D x 24"H; portable.
$520 for base unit with timer
only. Add $160 for counter to
allow pacing by external flow
meter, $225 for mechanical re-
frigeration, $35 for electric
heater.
112
-------
Figure 10. Quality Control Equipment Company
ttodftl CVE SaavJLer
Photograph courtesy of Quality Control Equipment Company
113
-------
General Comments; Unit was developed by Dow Chemical
and is manufactured under license.
It uses a patented vacuum system
which delivers a volumetrically
controlled sample on signal.
Liquid is lifted through suction
tube into a sample chamber (which
is connected to the sample con-
tainer) with a float check valve.
When the chamber is filled to the
desired level it is automatically
closed to vacuum, the pump shuts
off, and the sample is forcibly
drawn into the sample container.
The suction line drains by gravity
to the source. An option provides
an 80 psi blow-down of the sampling
train just prior to sampling assur-
ing that no old material remains
in the submerged lower end of the
suction tube, helps clean the lines
of any accumulations which might
clog or plug, and provides a fresh
air purge of the entire system.
QCEC Model CVE Evaluation
1. Should be relatively free from clogging due to lack of
bends and fittings in sample train and optional 80 psi
purging feature.
2. Obstruction of flow will depend upon way user mounts
end of sampling tube.
3. Should operate fairly well over the entire range of
flow conditions.
4. Movement of solids should not hamper operation.
5. No automatic starter. Optional purge serves a self-
cleaning function.
6. Can collect samples paced by either built-in timer or
external flow meter and composite them in a suitable
container. Representativeness of sample will depend
upon user mounting of intake tube.
7. Unit does not appear suitable for collection of float-
ables or coarser bottom solids.
114
-------
8. Standard unit has insulated sample container with ice
chamber; automatic refrigeration is optional. Appears
to offer good sample protection and freedom from
precontamination.
9. Unit would appear to function satisfactorily in a
manhole environment.
10. Cannot withstand total immersion.
11. Thermostatically controlled heater is available for
applications in freezing ambients.
12. Maximum lift of 20 feet does not place too severe a
restriction on use of the unit.
115
-------
Designation:
Manufacturer :
Sampler Intake:
Gathering Method
Sample Lift :
Line Size :
Sample Flow Rate
Sample Capacity:
Controls:
Power Source:
Sample Refrigerator:
Construction Materials
Basic Dimensions
Base Price:
QCEC MODEL E
Quality Control Equipment Company
613 Fleur Drive
Des Moines, Iowa 50315
Phone (515) 285-3091
Dipping bucket.
Mechanical; dipper on sprocket-
chain drive.
To suit; manufacturer claims no
reasonable limit to working depth
Not applicable.
Not applicable.
Dipping bucket holds 2 ounces;
user supplies sample composite
container to suit.
Sampling cycles can either be
started at fixed, selected inter-
vals by a built-in timer or in
response to signals from an ex-
ternal flow meter.
115V ac
None
Dipper is stainless steel;
sprockets and chain are corrosion-
resistant cast iron (stainless
available), supports are provided
by user.
Upper unit is 8"W x 15 1/2"D
x 14"H; lower unit is 3" x 4 1/2",
$875 plus $20 per foot beyond 6';
add $375 for stainless steel
sprockets and chain plus $40 per
foot beyond 6 *.
116
-------
General Comments; Manufacturer states that unit was
designed as a permanently installed
sampler for the most difficult ap-
plications such as packing houses,
steel mills, pulp mills, and
municipal applications. Unit must
be custom installed by user. Min-
imum water depth required is 4".
QCEC Model E Evaluation
1. Clogging of sampling train is unlikely; however, the
exposed chain-sprocket drive is vulnerable to jamming
by rags, debris, etc.
2. Unit provides a rigid obstruction to flow-
3. Unit should operate over full range of flows.
4. Movement of solids could jam or physically damage unit.
5. No automatic starter; no self cleaning features.
6. Collects fixed size aliquots paced by built-in timer
or external flow meter and composits them in a suit-
able container.
7. Does not appear well suited for collecting either
floatables or coarser bottom solids.
8. No sample collector provided.
9. Unit is capable of manhole operation.
10. Unit is weatherproof; cannot withstand total immersion.
11. Unit is not suitable for prolonged operation in
freezing ambients.
12. Unit would appear impractical for very long lifts (say
above 60 feet).
117
-------
Designation:
Manufacturer :
Sampler Intake
Gathering Method
Sample Lift :
Line Size:
Sample Flow Rate;
Sample Capacity:
Controls:
P ower S ource:
Sample Refrigerator
SERCO MODEL NW-3
Sonford Products Corporation
100 East Broadway, Box B
St. Paul Park, Minn. 55071
Phone (612) 459-6065
Twenty four
pling lines
1/4" I.D. vinyl sam-
r__..e are connected to in-
dividual ports in a stainless
steel sampling head (approx. 4" dia)
and protected by a stainless steel
shroud.
Suction lift from vacuum in
evacuated sample bottles.
3 feet standard; sample size re-
duced as lift increases; 8 to
10 feet appears practical upper
limit.
1/4" I.D.
Varies with filling time, atmos-
pheric pressure, bottle vacuum,
sample lift, etc.
24-16 ounce French square glass
bottles are provided. Sample
sizes up to 400 ml can be obtained
depending upon lift, bottle vacuum
and atmospheric pressure; 200 ml
is typical.
A spring driven clock via a change-
able gearhead rotates an arm which
trips line switches at a predeter-
mined time interval triggering
sample collection. Sampling in-
tervals of 2, 3, or 8 hours and
5, 10, or 30 minutes are available
in addition to the standard 1 hour
interval.
Spring driven clock.
Has ice cavity for cooling.
118
-------
v£>
Figure 11. SERCO Model NW-3 Sampler
Photograph courtesy of Sonford Products Corp.
-------
Construction Materials: Aluminum case with rigid poly-
styrene insulation; aluminum
bottle rack; glass bottles with
rubber stoppers and rubber lines
through switch plate, plastic
connectors and vinyl lines to
stainless steel sampling head.
Basic Dimensions; 15 1/2"W x 15 1/2"D x 26 3/4"H;
empty weight is 55 pounds;
portable.
Base Price: $920 including vacuum pump.
Serco Model NW-3 Evaluation
1. Sampling head is vulnerable to blockage of a number of
sampling ports at one time by paper, rags, plastic,
etc. Sampling train is an unobstructed 1/4 inch
passageway which will pass small solids. No pump
to clog.
2. Sampling head and shroud are simply dangled in the
flow stream to be sampled. No rigid obstruction.
3. Low sampling velocities make representativeness of
samples questionable at high flow rates. Length of
protective shroud limits immersion to about 1 foot
before vinyl sampling tubes are exposed to flow.
4. Sampling head would appear to be vulnerable to clog-
ging if in bed load. Stainless steel shroud offers
good protection against movement of solids in flow
stream.
5. Optional automatic starter available which allows
remote starting by either clock or float mechanism.
Otherwise must be started manually. No self cleaning
features. Proper cleaning of all 24 sampling lines
would be difficult and time consuming in the field.
6. Collects discrete samples at preset times.
7. Appears unsuitable for collection of samples of either
floatable materials or coarser bottom solids.
8. Provision for ice cooling affords some sample protec-
tion for a limited time. Limited lift may require
120
-------
placing sampler case in a vulnerable location. Use of
individual sampling lines eliminates cross contamina-
tion possibility.
9. Unit will pass through a 20" circle. Case has base
opening where sampling line bridle emerges. Should
be capable of manhole operation.
10. Case will fill with fluid if submerged. Spring clock
and drive mechanism then becomes vulnerable, especially
if fluid contains solids.
11. No standard provision for heating case. Freezing of
sampling lines appears a distinct possibility.
12. Practical upper lift limit of 8 to 10 feet poses
restrictions on operating head conditions.
121
-------
Designation:
Manufacturer:
Sampler Intake:
Gathering Method
Sample Lift;
Line Size:
Sample Flow Rate;
Sample Capacity:
Controls:
Power Source:
Sample Refrigerator
SERCO MODEL TC-2
Sonford Products Corporation
100 East Broadway, Box B
St. Paul Park, Minn. 55071
Phone (612) 459-6065
Provided by user
standard 2" pipe
; sampler has
inlet.
External head to provide flow
through a sample reservoir from
which a mechanical arm actuated by
an air cylinder with a dipper cup
extracts a sample aliquot and
transfers it to a funnel where it
is gravity fed to a composite
bottle.
Not applicable.
Smallest line in sampling train is
the one connecting the funnel to
the tube leading to the sample
bottle; it appears to be about
3/4".
Recommended flow rate through sam-
pler is 10 to 15 gpm. Reservoir
is designed so that sufficient
velocity and turbulence will pre-
vent settling or separation.
in
Sampling dippers are available
either 10 or 20 ml capacity; a
2-gallon sample composite container
is provided.
Takes samples either on signal from
sauipj_fc;B eitiier on sj-guaj.
a preset timer or from signals
riginating from an external flow
iter .
or:
meter
115V ac electrical plus low pres'
sure plant air.
Automatic refrigeration unit
thermostatically controlled to
maintain sample temperature at
4° to 10°C.
122
-------
Construction Materials; Sampling arm is all brass and
stainless steel; dipper cup is
plastic; cabinet is stainless
steel with zinc plated framing and
porcelain interior.
Basic Dimensions: 38 1/4"W x 24 1/4"D x 34 1/2"H
plus sampling arm which extends
up 23 1/2" and back about a foot.
Designed for fixed installation.
Base Price; $2,495.
General Comments; A permanent installation for con-
tinuous composite sampling. The
actual sampling device is simply
an open cup which is large enough
to permit sampling all sizes of
suspended solids normally encoun-
tered in wastewater flows. Because
the cup is emptied by turning it
over completely, the entire sample
is removed and there is little
likelihood of solids being retained
in the cup.
Serco Model TC-2 Evaluation
1. Should be free from clogging. Sampling intake must be
designed by user.
2. Sampler itself offers no flow obstruction.
3. Should operate well over entire range of flow
conditions.
4. Movement of solids should not hamper operation.
5. Designed for continuous operation; no automatic
starter. Continuous flow serves a self cleaning
function and should minimize cross-contamination.
6. Can collect either flow proportional composite or
fixed time interval composite. Representativeness
of sample will be a function of sampling intake
which is not a part of this unit.
7. Collection of floatables and coarser bottom solids will
depend upon design of sampling intake.
123
-------
8. Automatic refrigeration maintains samples at 4° to
10°C. Offers good sample protection and freedom from
p r e c o n t am i n a t i o n .
9. Not designed for confined space or manhole operation.
10. Cannot withstand total immersion.
11. Not designed for use in freezing ambient conditions.
12. Operating head is provided by user.
124
-------
Designation;
Manufacturer:
Sampler Intake:
Gathering Method;
Sampler Lift;
Line Size:
Sampler Flow Rate
Sample Capacity;
Controls :
Power Source:
Sample Refrigerator
Construction Materials
Basic Dimensions :
Base Price:
SIGMAMOTOR MODEL WA-1
Sigmamotor, Inc.
14 Elizabeth Street
Middleport, New York 14105
Phone (716) 735-3616
End of 25 foot long suction tube
installed to suit by user.
Suction lift from peristaltic
pump .
22 foot maximum lift.
1/8" I.D.
60 ml per minute.
Adjustable size aliquots of from
60 to 1,800 ml are composited in
a 2 1/2 gallon sample container.
Built-in timer triggers unit once
every 30 minutes. Model WA-2 has
an adjustable timer allowing
sampling interval to be set from
1 to 30 minutes.
115V ac. Model WD-1 comes with a
N. Cad battery pack and charger.
None. Model WA-2R has an auto-
matic refrigeration unit for cool-
ing sample compartment.
Sample train is tygon and poly-
ethylene; case is ABS plastic.
WA-1, WA-2, WD-1, WD-2 - 13 1/2"W
x 10"D x 14"H;
WA-2R - 21 1/2"W x 21 1/4"D x 34"H;
weights are WA-1 18 pounds,
WA-2 19 pounds, WD-1 28 pounds,
WD-2 29 pounds, WA-2R 90 pounds;
all portable.
$400 WA-1; $600 WD-1
$450 WA-2; $650 WD-2; $700 WA-2R
125
-------
General Comments: Charge time for battery operated
models is 16 hours. On model WA-2R
the pump automatically purges the
tubing at the end of each sampling
cycle to help prevent bacterial
growth in the line.
Sigmamotor Model WA-1 Evaluation
1. Obstruction or clogging will depend upon user installa-
tion of intake line; the peristaltic pump can tolerate
solids but the 1/8" I.D. tubing size is rather small.
2. Obstruction of flow will depend upon user mounting of
intake line.
3. Should operate reasonably well under all flow condi-
tions, but fairly low intake velocity could affect
representativeness of sample at high flow rates.
4. Movement of solids within the fluid flow should not
affect operation adversely.
5. No automatic starter. Only the refrigerated model
has an automatic purging feature for self-cleaning.
6. Unit takes fixed time interval samples paced by a
built-in timer and composits them in a suitable
container.
7. Unit does not appear suitable for collecting either
floatables or coarser bottom solids.
8. Units offer reasonable sample protection; a refriger-
ated model is available to maintain sample at a pre-
set temperature.
9. Unit appears capable of manhole operation.
10. Unit cannot withstand total immersion.
11. Unit cannot withstand freezing ambients.
12. 22 foot maximum lift does not place a great operating
restriction on unit. All but the refrigerated model
will pass through a standard manhole.
126
-------
Designation;
Manufacturer:
Sampler Intake;
Gathering Method
Sample Lift;
Line Size:
Sample Flow Rate:
Sample Capacity:
Controls:
Power Source;
Sample Refrigerator:
Construction Materials
Basic Dimensions:
Base Price:
General Comments
SIGMAMOTOR MODEL WA-3
Sigmamotor, Inc.
14 Elizabeth Street
Middleport, New York 14105
Phone (716) 735-3616
End of 25 foot long suction tube
installed to suit by user.
Suction lift from peristaltic pump.
22 foot maximum lift.
1/4" I.D.
50 ml per minute.
Adjustable size aliquots of from
60 to 1,800 ml are composited in a
2 1/2 gallon sample container.
Built-in timer triggers unit once
every 30 minutes. Model WA-4 has
an adjustable timer allowing
sampling interval to be set from
1 to 30 minutes.
115V ac. Model WD-3 comes with a
N. Cad battery pack and charger.
None
Sample train is tygon and poly-
ethylene; case is ABS plastic.
13 1/2"W x 20"D x 14"H; weights are
WA-3 22 pounds, WA-4 23 pounds,
WD-3 28 pounds, WD-4 29 pounds;
all portable.
$650 WA-3; $850 WD-3
$700 WA-4; $900 WD-4
Charge time for battery operated
models is 16 hours. Manufacturer
recommends this model for sampling
streams with long fibers and
larger particles.
127
-------
Sigmamotor Model WA-3 Evaluation
1. Obstruction or clogging will depend upon user installa
tion of intake line; the unobstructed 1/4" I.D. sam-
pling line and the peristaltic pump should tolerate
solids fairly well.
2. Obstruction of flow will depend upon user mounting of
intake line.
3. Should operate reasonably well under all flow condi-
tions, but fairly low intake velocity could affect
representativeness of sample at high flow rates.
4. Movement of solids within the fluid flow should not
affect operation adversely.
5. No automatic starter; no self-cleaning feature.
6. Unit takes fixed time interval samples paced by a
built-in timer and composits them in a suitable
container.
7. Unit does not appear suitable for collecting either
floatables or coarser bottom solids.
8. Units offer reasonable sample protection, but offers
no refrigeration.
9. Unit appears capable of manhole operation.
10. Unit cannot withstand total immersion.
11. Unit cannot withstand freezing ambients.
12. 22 foot maximum lift does not place a great operating
restriction on unit.
128
-------
Designation;
Manufacturer:
Sampler Intake:
Gathering Method
Sample Lift;
Line Size;
Sample Flow Rate
Sample Capacity;
Controls:
Power Source;
Sample Refrigerator;
Construction Materials
Basic Dimensions;
Base Price:
General Comments:
SIGMAMOTOR MODEL WDPP-2
Sigmamotor, Inc.
14 Elizabeth Street
Middleport, New York 14105
Phone (716) 735-3616
End of 25 foot long suction tube
installed to suit by user.
Suction lift from peristaltic pump.
22 foot maximum lift.
1/8" I.D.
60 ml per minute.
Adjustable size aliquots of from
36 to 480 ml are composited in a
2 1/2 gallon sample container.
System responds to a switch closure
from an external flow meter and
takes an adjustable size sample.
Model WDP-2 varies the number of
samples in response to a varying
signal from a user supplied trans-
mitter. The unit will deliver a
30 second sample (nominally 30 ml)
every 4 minutes at maximum signal
strength, every 8 minutes at
one-half signal strength, etc.
115V ac or 12V dc; unit comes with
a N. Cad battery pack and charger.
None standard.
Sample train is tygon and poly-
ethylene; case is ABS plastic.
13 1/2"W x 10"D x 14"H; weighs
25 pounds; portable.
$680 WDPP-2; $770 WDP-2
Charge time for batteries is
16 hours.
129
-------
Sigmamotor Model WDPP-2 Evaluation
1. Obstruction or clogging will depend upon user installa
tion of intake line; the peristaltic pump can tolerate
solids but the 1/8" I.D. tubing size is rather small.
2. Obstruction of flow will depend upon user mounting of
intake line.
3. Should operate reasonably well under all flow condi-
tions, but fairly low intake velocity could affect
representativeness of sample at high flow rates.
4. Movement of solids within the fluid flow should not
affect operation adversely.
5. No automatic starter; no self-cleaning feature.
6. Unit takes flow proportional samples paced by an
external flow meter and composits them in a suitable
container.
7. Unit does not appear suitable for collecting either
floatables or coarser bottom solids.
8. Units offer reasonable sample protection, but offer
no refrigeration.
9. Units appear capable of manhole operation.
10. Units cannot withstand total immersion.
11. Unit cannot withstand freezing ambients.
12. 22 foot maximum lift does not place a great operating
restriction on unit.
130
-------
Designation
Manufacturer:
Sampler Intake;
Gathering Method
Sample Lift;
Line Size;
Sample Flow Rate
Sample Capacity;
Controls:
Power Source:
Sample Refrigerator
Construction Materials
Basic Dimensions:
Base Price:
General Comments
SIGMAMOTOR MODEL WM-1-24
Sigmamotor, Inc.
14 Elizabeth Street
Middleport, New York 14105
Phone (716) 735-3616
End of 25 foot long suction tube
installed to suit by user.
Suction lift from peristaltic pump.
22 foot maximum lift.
1/8" I.D.
60 ml per minute.
Unit takes 24 discrete 450 ml
samples.
Sampling frequency adjustable from
one every 10 minutes to one every
hour. External flow meter pacing
available on special order.
115V ac. Model WM-2-24 comes with
a N. Cad battery pack and charger.
None. WM-1-24R has an automatic
refrigeration unit for cooling
sample compartment.
Sample train is tygon and poly-
ethylene; case is ABS plastic.
WM-1-24; WM-2-24 - 14 1/2"W x 13"D
x 24 1/2"H; WM-1-24R - 20"W x 21"D
x 33 1/2"H; weights are
WM-1-24 28 pounds,
WM-2-24 36 pounds,
WM-1-24R 125 pounds; all portable.
$1,050 WM-1-24; $1,200 WM-2-24;
$1,525 WM-1-24R
Charge time for battery operated
model is 16 hours. The pump auto-
matically purges the tubing at the
131
-------
end of each sampling cycle to help
prevent bacterial growth in the
line and minimize cross-
contamination .
Sigmamotor Model WM-1-24 Evaluation
1. Obstruction or clogging will depend upon user installa-
tion of intake line; the peristaltic pump can tolerate
solids but the 1/8" I.D. tubing size is rather small.
2. Obstruction of flow will depend upon user mounting of
intake line.
3. Should operate reasonably well under all flow condi-
tions, but fairly low intake velocity could affect
representativeness of sample at high flow rates.
4. Movement of solids within the fluid flow should not
affect operation adversely.
5. No automatic starter. Unit has an automatic purging
feature for self-cleaning.
6. Unit takes 24 fixed interval samples paced by a
built-in timer and deposits them in individual
containers.
7. Unit does not appear suitable for collecting either
floatables or coarser bottom solids.
8. Units offer reasonable sample protection; a refriger-
ated model is available to maintain sample at a pre-
set temperature.
9. Units appear capable of manhole operation.
10. Units cannot withstand total immersion.
11. Unit cannot withstand freezing ambients.
12. 22 foot maximum lift does not place a great operating
restriction on unit. All but the refrigerated model
will pass through a standard manhole.
132
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Designation;
Manufacturer:
Sampler Intake;
Gathering Method:
Sample Lift:
Line Size;
Sample Flow Rate:
Sample Capacity:
Controls:
Power Source:
Sample Refrigerator;
Construction Materials
Basic Dimensions:
SIRCO SERIES B/ST-VS
Sirco Controls Company
8815 Selkirk Street
Vancouver, B.C.
Phone 261-9321
End of 25 foot sampling tube in-
stalled to suit by user.
Suction lift by vacuum pump.
Up to 22 feet vertical and 100 feet
horizontal.
3/8" I.D.
Depends upon lift.
Sample volume is adjustable between
10 to 1000 ml; either composited in
2-, 3-, or 5-gallon jars or sequen-
tial in either 12 or 24 jars of
either 1 pint or 1 quart capacity.
"Metermatic" chamber (adjustable)
controls sample volume. Available
with built-in timer for preset
time interval sampling or for con-
nection to external flow meter for
flow porportional sampling or both.
Purge timer.
Either 110V ac or 12V dc lead
zinc or nickel cadmium battery
or combination.
Available with thermostatically
controlled refrigerated sample
compartment.
PVC sampling tube, weatherproof
steel enclosure standard; all
stainless steel construction
available.
A fairly large unit
30 cubic feet) that
portable.
(about 20-
is not easily
133
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Figure 12. Sirco Series B/ST-VS Sampler
Photograph courtesy of Sirco Controls Company
-------
Base Price; $1,760 non-refrigerated composite
sampler
$2,180 refrigerated composite
sampler
$2,485 non-refrigerated 12 jar
sequential
$2,670 non-refrigerated 24 jar
sequential
$2,770 refrigerated 12 jar
sequential
$2,950 refrigerated 24 jar
sequential
General Comments; Signal from flow meter or timer
starts vacuum/compressor pump as
well as purge timer. Compressor
side of pump purges sample pick-up
tube until purge timer times out.
Sequence changes and vacuum side
of pump evacuates metering chamber
and draws sample in to the desired
capacity. After obtaining the de-
sired amount of sample, the com-
pressor side of pump is used to
forcibly discharge sample from
metering chamber into sample
collector.
Should plugging of the sample
pick-up tube occur, an automatic
timer switch uses the compressor
side to blow out the tube. This
sequence repeats itself as often
as needed to obtain the exact
amount of sample required. Purging
also takes place before and after
each sample is taken.
Manufacturer states this unit is
especially designed to sample un-
treated raw sewage or high con-
sistency industrial waste as it is
capable of taking solids up to 3/8"
in diameter including rags, fibers,
and similar. The only wetted parts
are the sample tubing and volume
control chamber.
135
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Sirco Series B/ST-VS Evaluation
1. Should be relatively free from clogging due to lack of
bends and fittings in sample train and high pressure
purging feature.
2. Obstruction of flow will depend upon way user mounts
the end of the sampling tube.
3. Should operate well over the entire range of flow
conditions .
4. Movement of solids should not hamper operation.
5. No automatic starter. Power purge serves a self-
cleaning function.
6. Can collect external flow meter or built-in timer paced
samples either sequential or composite. Representa-
tiveness of sample will depend upon user mounting of
intake tube.
7. Unsuitable for collection of floatables or coarser
bottom solids without specially designed intake by
user.
8. Automatic refrigeration (adjustable temperature)
available. Offers good sample protection and freedom
from precontamination.
9. Not designed for confined space or manhole operation.
10. Cannot withstand total immersion.
11. Thermostatically controlled heaters and fans are
available for applications in freezing ambients.
12. Maximum lift of 22 feet does not place too severe
a restriction on use of the unit.
136
-------
Designation;
Manufacturer:
Sampler Intake;
Gathering Method
Sample Lift;
Line Size:
Sample Flow Rate:
Sample Capacity;
Controls:
Power Source:
Sample Refrigerator
SIRCO SERIES B/IE-VS
Sirco Controls Company
8815 Selkirk Street
Vancouver, B.C.
Phone 261-9321
2" I.D. guide pipe for sampling
cup with perforations in lower
end to maximum flow level.
Mechanical; a weighted sampling
cup is lowered through a guide
pipe into the effluent by a hoist
mechanism powered by a reversing
gear motor. At the upper travel
stop the cup empties sample into
a sample container by gravity.
Up to 200 feet.
Smallest line in sampling train
appears to be about 3/8" tube
connecting collection funnel to
sample reservoir.
Not applicable.
Sample cup has 100 ml capacity;
either composited in 2-, 3-, or
5-gallon jars or sequential in
either 12 or 24 jars of either
1 pint or 1 quart capacity.
Available with built-in timer for
pre-set time interval sampling or
for connection to external flow
meter for flow proportional
sampling or both.
Either 110V ac or 12V dc lead zinc
or nickel cadmium battery or
combination.
Available with thermostatically
controlled refrigerated sample
compartment.
137
-------
Construction Materials
Basic Dimensions:
Base Price:
General Comments:
PVC sampling cup and guide tube,
weatherproof steel enclosure
standard; all stainless steel con-
struction available.
About 3'W x 2'D x 5'H. Not easily
portable.
$1,380 non-refrigerated composite
sampler
$1,989 refrigerated composite
sampler
$1,995 non-refrigerated 12 jar
sequential
$2,185 non-refrigerated 24 jar
sequential
$2,585 refrigerated 12 jar
sequential
$2,850 refrigerated 24 jar
sequential
This unit was designed for high
lift applications. According to
the manufacturer it is not recom-
mended for high consistency in-
dustrial effluent or raw sewage
where large pieces of fiber, rags,
papers, etc. are present.
Sirco Series B/IE-VS Evaluation
1. Cup in guide pipe appears susceptible to sticking and
clogging. Guide pipe perforations are vulnerable to
obstruction and clogging.
2. The 2" I.D. guide pipe must pass completely through the
flow stream to be sampled presenting a serious rigid
obstruction to flow.
3. Does not appear capable of uniform operation over full
range of flow conditions.
4. Solids could collect in guide pipe and hamper cup
travel.
5. No automatic starter. No self cleaning features.
6. Can collect flow meter or timer paced samples either
sequential or composite. Representativeness of sample
138
-------
will be dependent upon conditions at end of guide tube
but appear highly variable and questionable.
7. Not suitable for collection of floatables or coarser
bottom solids .
8. Automatic refrigerator (adjustable temperature) avail-
able. Offers good sample protection but vulnerable to
cross contamination in sequential mode.
9. Not designed to operate in manholes.
10. Cannot withstand total immersion.
11. Thermostatically controlled heaters and fans are
available for applications in freezing ambients.
12. 200 foot lift (or more) gives this unit virtually
unrestricted use.
139
-------
Designation;
Manufacturer:
Sampler Intake:
Gathering Method
Sample Lift:
Line Size:
Sample Flow Rate
Sample Capacity:
Controls:
Power S ource:
SIRCO SERIES B/DP-VS
Sirco Controls Company
8815 Selkirk Street
Vancouver, B.C.
Phone 261-9321
Provided by user.
inlet pipe.
Sampler has 2"
External head to provide flow
through sampler and back to sewer.
On signal a liquid diverter mecha-
nism is energized for a preset
number of seconds and sample is
drawn into a metering chamber.
After the desired amount of sample
is obtained, a solenoid valve at
the bottom of the metering chamber
is actuated and the sample is dis-
charged by gravity into the sample
j ar.
Not applicable.
Smallest line size appears to be
about 3/8 inch tube leading to
sample jar.
Depends upon user's installation;
no recommended minimum.
Sample metering chamber adjustable
from 50 to 500 ml; either compos-
ited in 2-, 3-, or 5-gallon jars or
sequential in either 12 or 24 jars
of either 1 pint or 1 quart
capacity.
Available with built-in timer for
pre-set time interval sampling or
for connection to external flow
meter for flow proportional sam-
pling or both.
Either 110V ac or 12V dc lead zinc
or nickel cadmium battery or
combination.
140
-------
Sample Refrigerator;
Construction Materials
Basic Dimensions:
Base Price:
General Comments:
Available with thermostatically
controlled refrigerated sample
compartment.
Sampling train is stainless steel
and plastic; weatherproof steel
enclosure standard; all stainless
steel construction available.
About 3'W x 2'D x 5'H. Designed
for fixed installation.
$1,550 non-refrigerated composite
sampler
$1,870 refrigerated composite
sampler
$2,190 non-refrigerated 12 jar
sequential
$2,360 non-refrigerated 24 jar
sequential
$2,460 refrigerated 12 jar
sequential
$2,640 refrigerated 24 jar
sequential
This unit was designed for in-
stallations where the sampler must
be some distance, say more than
100 feet, from the sample pick-up
point. It is recommended by the
manufacturer for treated sewage
or final effluent.
Sirco Series B/DP-VS Evaluation
1. Diverter mechanism could be subject to clogging (manu-
facturer only recommends unit for treated sewage or
final effluent). Sampling intake must be designed by
user.
2. Sampler itself offers no flow obstruction.
3. Should be capable of operating over entire range of
flow conditions.
4. Movement of solids should not hamper operation.
141
-------
5. No automatic starter. Continuous flow serves a
self-cleaning function and should reduce cross-
contamination .
6. Can collect flow meter or timer paced samples either
sequential or composite. Representativeness of sample
will depend upon design of sampling intake which is
not a part of this unit.
7. Unsuitable for collection of floatables or coarser
bottom solids .
8. Automatic refrigerator (adjustable temperature) avail-
able. Offers good sample protection but vulnerable to
slight cross-contamination in sequential mode.
9. Specifically designed for installation remote from
sample pick-up point. Not suitable for manhole
operation.
10. Cannot withstand total immersion.
11. Thermostatically controlled heater and fans are
available for applications in freezing ambients.
12. Operating head is provided by user.
14:
-------
Designation:
Manufacturer:
Sampler Intake:
Gathering Method
Sample Lift:
Line Size:
Sample Flow Rate
Sample Capacity:
Controls:
Power Source;
Sample Refrigerator:
Construction Materials
Basic Dimensions;
Base Price:
General Comments:
SIRCO MODEL PII-A
Sirco Controls Company
8815 Selkirk Street
Vancouver, B.C.
Phone 261-9321
End of 20 foot sampling tube
installed to suit by user.
Suction lift by vacuum pump.
Up to 18 feet.
1/4" I.D.
Depends upon lift.
Sample volume adjustable between
10 and 200 ml; composited in 1-,
2-, or 3-gallon jar.
Adjustable chamber controls sample
volume. Built-in timer allows
adjusting sample cycle from
3 minutes to 40 hours.
12V dc lead zinc or nickel cadmium
battery.
None
PVC sampling tube and case.
12" diameter x 28"H not including
battery case; weighs 50 pounds
empty; portable.
$1,387. Add $95 for heavy duty
battery and case; add $182 for
battery with charger; add $168
for N. Cad battery instead of
standard battery.
Signal from timer starts vacuum/
compressor pump. Compressor side
of pump purges sample intake tube,
sequence changes and vacuum side
of pump evacuates metering chamber
and draws desired amount of sample.
143
-------
Compressor side of pump then dis-
charges sample into sample con-
tainer. Should plugging of the
sampling tube occur, the pump is
switched to the compressor side to
blow out the tube. This sequence
is repeated until the desired
amount of sample is collected.
Purging also takes place before
and after each sample is taken.
Manufacturer states that the unit
is especially designed to sample
untreated raw sewage or high con-
sistency industrial waste contain-
ing rags, fibers, etc.
Sirco Model PII-A Evaluation
1. Should be fairly free from clogging due to lack of
bends and fittings in sample train and high pressure
purging feature.
2. Obstruction of flow will depend upon way user mounts
the end of the sampling tube.
3. Should operate equally well under the entire range of
flow conditions.
4. Movement of solids should not hamper operation.
5. No automatic starter. Power purge serves a self
cleaning function.
6. Can collect a composite of timer paced samples only.
Representativeness of sample will depend upon user
mounting of intake tube.
7. Unsuitable for collection of floatables or coarser
bottom solids without special designed intake by user.
8. No refrigeration. Sample appears fairly well pro-
tected in case.
9- Designed to operate in manhole area.
10. Cannot be totally immersed.
144
-------
11. Cannot withstand freezing ambient.
12. Maximum lift of 18 feet when coupled with small size
allows considerable flexibility in use of the unit.
145
-------
Designation:
Manufacturer:
Sampler Intake:
Gathering Method
Sample Lift :
Line Size :
Sample Flow Rate
Sample Capacity:
Controls :
Power Source :
S ample Refrigerator:
Construction Materials
Basic Dimensions:
Base Price:
SONFORD MODEL HG-4
Sonford Products Corporation
100 East Broadway, Box B
St. Paul Park, Minn. 55071
Phone (612) 459-6065
Parabolic port in a 3/4" I.D.
rigid tube.
Mechanical; sampling tube is
rotated down into the flow where it
fills through the port by gravity;
an electric motor rotates the tube
up and the sample flows by gravity
into the container.
Telescoping sampling tubes may be
adjusted to reach down to 21 inches
from the bottom of sampler.
3/4" I.D.
Varies with tube angle.
Varied aliquot sizes of 10, 20 or
30 ml are composited in a single
1-gallon container.
Sampling cycle may be triggered at
preset time intervals from built-in
electrical timer or on signal from
external flow meter.
110V ac standard; battery
optional.
Has ice cavity for cooling.
Aluminum outer case with rigid
insulation.
13 5/16"W x 12 5/16"D x 13"H plus
clearance for oscillating sampling
tube which varies depending upon
telescoping adjustment. Portable.
$325 electric; $495 with battery.
146
-------
Sonford Model HG-4 Evaluation
1. Does not appear capable of sampling a particle large
enough to clog it; could be affected by rags or paper;
no pump to clog.
2. Sampling tube presents a flow obstruction during
sampling period only.
3. Low sampling velocities make representativeness of
samples questionable at high flow rates. Does not
appear tolerant of variable depth flows.
4. Unless mounted so that sampling tube oscillates in
flow direction, large solids could cause damage.
Appears susceptible to fouling by stringy materials
which could wrap around sampling tube.
5. No provision for automatic staring. No self cleaning
features.
6. Collects fixed size samples at either preset time in-
tervals or on signal from external flow meter and
composits them in a single container.
7. Appears unsuitable for collection of samples of either
floatable materials or coarser bottom solids.
8. Provision for ice cooling affords some sample protec-
tion for a limited time. Limited lift may require
placing sampler in a vulnerable location. Cross con-
tamination appears very likely.
9. Unit has a small case but requires clearance for
oscillating sampling tube. Case has unsealed opening
for movement of same.
10. Unit cannot tolerate submersion.
11. No standard provision for heating case. Ice buildup
in sampling tube appears a real possibility.
12.
Limited lift and restrictions on liquid level varia-
tions severely limit range of operating head conditions
147
-------
Des ignation:
Manufacturer:
Sample Intake:
Gathering Method
Sample Lift:
Line Size:
Sample Flow Rate
Sample Capacity:
Controls:
Power S ource:
Sample Refrigerator:
Construction Materials
Basic Dimensions:
Bas e Price:
TMI FLUID STREAM SAMPLER
Testing Machines, Inc.
400 Bayview Avenue
Amityville, New York 11701
Phone (516) 842-5400
Stainless steel hollow cylindrical
body with a 1" inlet and mounted
submerged in the stream either on
four legs mounted to a bottom
plate or suspended from above if
in a weir or flume.
Forced flow due to pneumatic
ej ection.
Over 25 feet; depends upon air
pressure.
1/2" O.D.
Depends upon air pressure and
lift .
Aliquots of approximately 1 pint
are composited in a suitable con-
tainer provided by user.
User must provide air pressure
regulator if plant air supply is
not regulated; sampling interval
timer is adjustable to allow from
1 minute to 1 month to elapse
between aliquots; manual on-off
swit ch.
Compressed air supply of at least
20 psi, 100 psi maximum; 110V ac.
None .
Stainless steel and plastic.
Largest element will be user sup-
plied sample container; sampling
intake 4"W x 9"D x 8"H; timing
controller 12"W x 7"D x 15"H.
$660.
148
-------
General Comments: Sampler developed by International
Paper Company for use in the paper
industry for checking the loss of
useable fiber in effluent, taking
consistency samples, etc. Sampler
has performed well in flows to
1800 gpm and consistencies to
3.5 percent.
TMI Fluid Stream Sampler Evaluation
1. Sampler should be free from clogging.
2. Sampler intake offers rigid obstruction to flow.
3. Sampling chamber will fill immediately following end
of previous sample. Circulation through chamber would
appear to be limited, resulting in a sample not neces-
sarily representative of conditions in the sewer at
the time of next triggering signal.
4. Movement of small solids should not affect operation;
large objects could damage (or even physically destroy)
the in-water portion unless special protection is pro-
vided by user.
5. No automatic starter; no self-cleaning features.
6. Collects fixed size spot samples and composits them
in a suitable container; a 3-minute cycle interval
will deliver approximately 60 gallons in 24 hours.
7. Unsuitable for collection of either floatables or
coarser bottom solids without special intake designed
by user.
8. Sample container provided by user.
9. Not designed for manhole operation.
10. Cannot withstand total immersion.
11. Unit should be capable of operation in freezing
ambients.
12. Upper lift limit determined by air supply pressure.
149
-------
Designation:
Manufacturer:
TMI MARK 3B MODEL SAMPLER
Sampler Intake:
Gathering Method
S ample Lift:
Line Size:
Sample Flow Rate
Sample Capacity;
ControIs:
Power Source:
Sample Refrigerator:
Construction Materials
Tes ting
400 Bayview
Amityville,
Phone (516)
Machines, Inc
Avenue
New York
842-5400
11701
Twelve 1/4" I.D. vinyl sampling
lines are connected to individual
ports in a stainless steel sampling
head (approx. 4" dia) fitted with
a stainless steel filter having
approximately 930 1/8" diameter
holes .
Suction lift from vacuum in evac-
uated sample bottles.
Sample size reduced as lift in-
creases; 8 to 10 feet appears
practical upper limit with 20-ounce
bot ties.
1/4" I.D.
Varies with filling time, atmos-
pheric pressure, bottle vacuum,
sample lift, etc.
Twelve 20-ounce "Medicine Flat"
glass bottles are provided. Sample
sizes up to 400 ml can be obtained
depending upon lift, bottle vacuum
and atmospheric pressure; 300 ml
is typical.
A spring driven clock rotates an
arm which trips line switches at a
predetermined time interval trig-
gering sample collection. Sampling
intervals of 1/2 to 8 hours are
available.
Spring driven clock.
None .
PVC coated, light alloy case with;
glass bottles with rubber stoppers
and rubber lines through switch
150
-------
plate, plastic connectors and vinyl
lines to stainless steel sampling
head .
Basic Dimensions; 14 1/2" diameter x 26"H; empty
weight is 32 pounds; portable.
Base Price: $595 including vacuum pump.
Mark 4B model has 24 bottles at
$685 for 20-ounce size and $695 for
1 liter size.
General Comments; This unit was originally developed
by the Water Pollution Research
Laboratory in England and is manu-
factured by North Hants Engineering
Co. Ltd. under license from the
National Research Development
Corporation.
TMI Mark 3B Model Sampler Evaluation
1. Sampling head is vulnerable to blockage of a number
of sampling ports at one time by paper, rags, plastic,
etc. Sampling train is an unobstructed 1/4" passage-
way which will pass small solids. No pump to clog.
2. Sampling head and shroud are simply dangeled in the
flow stream to be sampled. No rigid obstruction.
3. Low sampling velocities make representativeness of
samples questionable at high flow rates. Vinyl sam-
pling tubes are exposed to flow.
4. Sampling head would appear to be vulnerable to clog-
ging if in bed load. Stainless steel filter offers
some protection against movement of solids in flow
stream.
5. No automatic starter; clocks allow setting a time
delay before sampling commences. No self cleaning
features. Proper cleaning of all 24 sampling lines
would be difficult and time consuming in the field.
6. Collects discrete samples at preset times from a fixed
point intake only.
7. Appears unsuitable for collection of samples of either
floatable materials or coarser bottom solids.
151
-------
8. No sample refrigeration. Limited lift may require
placing sampler case in a vulnerable location. Use of
individual sampling lines eliminates cross contamina-
tion possibility.
9. Unit will pass through a 15" diameter circle. Case
has base opening where sampling line bridle emerges.
10. Case will fill with fluid if submerged. Spring clock
and drive mechanism then becomes vulnerable, especially
if fluid contains solids.
11. No standard provision for heating case. Freezing of
sampling lines appears a distinct possibility.
12. Practical upper lift limit of 8 to 10 feet poses re-
strictions on operating head conditions.
152
-------
SECTION VII
REVIEW OF CUSTOM DESIGNED SAMPLERS
INTRODUCTION
As was noted in section VI, it has been the practice of
many project engineers to custom design one-of-a-kind sam-
plers for use in their projects due to a lack of availabil-
ity of suitable commercial equipment. In this section
several examples of such equipment are reviewed. Inasmuch
as there is no dearth of examples, it was necessary to be
rather selective in order to keep the overall size of this
report within manageable bounds. Several practical consid-
erations also favor less than 100 percent coverage. For
example, no attempt has been made to dig back into history
in order to examine older concepts and notions. It is felt
that any good features in older designs, having proved
themselves to be effective, would be incorporated in pres-
ent day equipment. Furthermore, the major emphasis has
been placed in recent EPA project experience.
DESCRIPTIVE FORMS AND EVALUATIONS
The same description and evaluation formats that were used
for reviewing the commercially available samplers in sec-
tion VI are used here with one exception. For these custom
designed one-of-a-kind samplers, prices in terms of today's
dollars are generally not available and, furthermore, the
inevitable engineering changes that one would introduce in
building equipment following a prototype would have cost
impacts that are not easily assessed.
The samplers have been given names to correspond with
either the developer or the project location. The descrip-
tive forms and evaluations presented on the following pages
are arranged roughly in chronological order of development,
and an index is provided on page x.
153
-------
Designation:
Project Location;
EPA Report No. :
Sampler Intake:
Gathering Method
Sample Lift:
Line Size:
Sample Flow Rate
Sample Capacity:
Controls:
Power Source;
Sample Refrigerator:
Construction Materials
AVCO INCLINED SEQUENTIAL SAMPLER
Tulsa, Oklahoma
11034 FKL 07/70
Inlet tube passes through an
aluminum tube which is hinged at
the top of the storm drainage
structure and has a polyethylene
float at the other end where the
inlet tube terminates with a sam-
pling probe.
Suction lift from peristaltic
pump .
Not stated, but probably 15 to
20 feet maximum.
1/8" I.D.
Not stated, but must be fairly low
for inclined sequential filling
scheme to be meaningful.
Unit sequentially fills a 60 ml
sample bottle, then a 2,000 ml
sample bottle, and repeats this
6 times, i.e., until it has filled
six 6Q-ml and six 2,000-ml bottles;
then it collects a composite sample
in a 5 gallon overflow bottle.
A limit switch on the hinged float
arm starts the pump when the flow
level exceeds a preset value.
When the flow level subsides the
pump is shut off.
12V dc marine battery.
None .
Polypropylene pick-up tube, tygon
and polyethylene connecting tubes,
polyethylene bottles; aluminum
frame, wood case.
154
-------
H
COLE-PARSER MASTERFLEX
TUBE-PUMP
II
PUMP MOTOR CONTROL
§) ^
O i,
VOLTAGE
REGULATOR
111 ij 111 li 11 irrri 1111111111111 ii 1111111 n
SWITCH
ALUMINUM CONDUIT
•VOLTAGE INVERTER
&
ffi J
IHH /
_>^:
^ /
1 TTaoo acaSi''
1
12 VOLT
MARINE TYPE
BATTERY
t— FOXBORO WATER PRESSURE
RECORDER
POLYPROPYLENE PICK-UP TUBE
POLYETHYLENE FLOAT
PRESSURE
BOX
CUTAWAY OF TYPICAL DRAIN
STRUCTURE
11 nri i ITJTI i mii nni 11111 11 111 ITTTTI n
Figure J.3. AVCO Inclined Sequential Sampler
Taken from EPA Report No. 11034 FKL 07/70.
-------
Basic Dimensions: Bottle rack is 28"W x 6"D x 16"H.
Both semi-stationary and portable
configurations were assembled.
General Comments: A pressure box in the flow and con-
nected to a Foxboro water pressure
recorder was used. Components in-
cluded a Cole-Farmer Masterflex
tube pump, Model No. 7015 and a
Terado power inverter (Allied
No. 21f4499). The sequential fill-
ing of the sample bottles is simply
performed by arranging their inlet
tubes in order along an inclined
manifold.
AVCO Inclined Sequential Sampler Evaluation
1. Clogging is likely in samples with high solids content
due to numerous 1/8" obstructions in sampling train
unless a filter is used; sampling probe points down-
stream and is near the surface due to float, but could
possibly be affected by paper, plastic, etc.
2. Float and arm will be completely submerged in a full
pipe flow situation and present an obstruction to flow
3. Unit should operate over full range of flows, but low
sample flow rate makes representativeness questionable
for high stream flows.
4. Movement of solids in the flow stream could hamper
operation.
5. Unit starts automatically when flow level rises above
a preset height; no self cleaning features.
6. Sequentially fills sample bottles from output of a
continuously running pump. Flow rate provides the
only timing function. Samples will be representative
of the near-surface water at best.
7. Unit may collect some floatables but is totally un-
suited for collecting coarser bottom solids.
8. No refrigeration. Some cross-contamination is guaran-
teed due to filling stem arrangement, especially for
60-ml bottles .
156
-------
9. Unit does not appear ideally suited for manhole
operation,
10. Unit cannot withstand total immersion.
11. Unit is unsuitable for use in freezing ambients.
12. A 15 to 20 foot lift limit puts slight restriction on
operating head conditions.
157
-------
Designation;
Project Location:
EPA Report No. ;
Sampler Intake;
Gathering Method
Sample Lift:
Line Size:
Sample Flow Rate:
Sample Capacity:
Controls:
Power Source:
Sample Refrigerator:
Construction Materials
Basic Dimensions:
SPRINGFIELD RETENTION BASIN
SAMPLER
Springfield, 111.
11023 - 08/70.
End of 920 foot long influent line
suspended 6" below water surface
from a float.
Suction lift from a screw rotor
pump .
Less than 14 feet required in this
application.
1 1/2" diameter lagoon influent
sample intake line, 4" diameter
lagoon effluent sample intake line.
Approximately 240 gph.
Intake lines discharged into
16 gallon sampling tanks. A con-
stant volume aliquot was obtained
each 30 minutes and composited in
a 5-gallon container.
A Lakeside Trebler scoop sampler
was used to remove aliquots from
sampling tanks. See discussion of
that sampler for details.
115V ac
Automatic thermostatically con-
trolled refrigerators were used to
house sample containers.
ABS plastic intake lines, PVC sam-
ple bottles, sampling tank appears
to be metal, pump materials not
given.
Components are distributed within
a general purpose equipment build-
ing; fixed installation.
158
-------
General Comments; Moyno pumps operating on a con-
tinuous basis were used to provide
sample flow through a 16 gallon
sampling tank. Two samplers were
constructed, one for the lagoon
influent and one for the effluent.
Since the Lakeside Trebler sampler
is evaluated elsewhere, no further
evaluation of this installation
will be made.
159
-------
Designat ion:
Project Location
EPA Report No.;
Sampler Intake:
Gathering Method:
Sample Lift:
Line Size:
Sample Flow Rate
Sample Capacity:
Controls:
MILK RIVER SAMPLER
Grosse Point Woods, Mich.
11023 FED 09/70
Overflow system influent sampler
intake was simply inlet of sub-
mersible pump suspended beyond
the bar screens within the transi-
tion structure between sewer and
wet well. Effluent sampler intake
was four 1-inch vertical suction
lines spaced evenly along the
210 foot long effluent weir which
drew their samples from points be-
tween the skimming baffle and weir
at a depth above the bottom of the
baffle and just below the outlet
weir .
Forced flow from submerged pump
for influent sampler; suction lift
from centrifugal pump for effluent
sampler.
Not stated.
Except for 1" diameter inlet lines
leading to effluent sampler
header, all sampling lines were
2" diameter.
Not stated.
Samplers collect adjustable grab
samples from the continuously
flowing 2-inch pipe streams, com-
posite them for variable periods
and hold them in a refrigerated
compartment for periods up to
about 3 hours.
The size of each grab sample is
controlled externally. Otherwise,
the sampling program is controlled
by a continuous punched paper tape
program which varies the collec-
tion time of each composite, the
160
-------
number of grab samples in each
composite, and each of the varia-
bles from one sampling time to
another.
Power Source; 115V ac
Sample Refrigerator; Automatic thermostatically con-
trolled refrigerated sample
compartments.
Construction Materials; Metal, plastic, and wood were used
in construction; no details were
given.
Basic Dimensions; Indoor portion of sampler is large,
perhaps 6'W x 3'D x 5'H or so;
fixed installation.
General Comments: This unit apparently functioned
fairly well on the project for
which it was designed. Since it
is a custom designed, fixed in-
stallation unit no complete
evaluation will be made.
161
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Designation:
Project Location
EPA Report No.;
Sampler Intake:
Gathering Method
Sample Lift;
Line Size:
Sample Flow Rate;
Sample Capacity;
Controls :
P ower Source;
Sample Refrigerator;
Construction Materials
Basic Dimensions:
ENVIROGENICS BULK SAMPLER
San Francisco, California
11024 FKJ 10/70
A metal container resembling an
inverted roadside mail box approx-
imately 14 1/2" long and 14" deep
with a 6" radius; hinged covers at
each end are mechanically con-
nected to function integrally upon
activation of an air cylinder.
Mechanical; the sampler intake
assembly is designed to fit a
special support structure which
must be installed in the manhole
chosen for sampling. It is
lowered to the bottom of the
invert whereupon the covers are
closed thereby trapping a plug of
the combined sewage inside the
sampler. The filled sampler was
then raised by winch to the
surface.
Depth of manhole in question. No
real limit.
Not applicable.
Not applicable.
Roughly 9 gallons maximum.
Manually operated.
Compressed air.
None .
Aluminum.
14 1/2"W x 12"D x 14"H plus
brackets and supporting structure,
etc.
162
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Envirogenics Bulk Sampler Evaluation
1. Unit should be free from clogging except for possibil-
ity of large debris interfering with flap closure.
2. Unit will completely obstruct flow the instant the
covers are closed, but will clear as raised.
3. Since sampler must be designed for the specific manhole
invert size in which it is to be used, it is suitable
for all flow conditions.
4. Movement of solids in flow will not affect operation
except where a significant bed load would prevent
sampler from coming to rest on the invert.
5. Unit is manually operated. Cleaning is accomplished
by the running sewage.
6. Sampler removes a "plug" of the sewage flow covering
the entire flow cross-section.
7. Unit should sample both, floatables and coarser bottom
solids.
8. Unit is not suitable for sample storage.
9. Unit is designed for manhole operation, but also re-
quires clear area above manhole for hoist and
personnel.
10. Unit operates totally immersed; if manhole is sur-
charging sample might be less representative.
11. Unit should operate in freezing ambients.
12. Unit is indifferent to operating head conditions.
163
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Designation:
Project Location:
EPA Report No. :
Sampler Intake:
Gathering Method
Sample Lift;
Line Size:
Sample Flow Rate
Sample Capacity:
Controls:
Power Source:
Sample Refrigerator;
Construction Materials
Basic Dimensions:
ROHRER AUTOMATIC SAMPLER MODEL I
Sandusky, Ohio
11022 ECV 09/71
Not clearly stated but presumably
the end of the suction line
mounted in the overflow conduit
just beyond the leaping weir.
Suction lift from diaphram pump.
Not stated but probably good for
at least 20 feet.
Smallest line would appear to be
the one connecting the diverter
head to the sample container, but
size is not given.
Not stated but presumably rather
large .
Unit collects twenty-four 1-pint
discrete samples plus a flow
proportional composite of up to
5-gallons.
Sampling is automatically started
when the leaping weir diverts flow
into the overflow flume. Discrete
samples were collected every
5 minutes paced by a built-in
timer adjustable from 5 to 60 min-
utes. Constant volume composite
aliquots are added for each
10,000 gallons of flow through the
overflow flume.
115V ac
None
Not stated.
None given but a fixed installation
located in a building specially
erected for the project.
164
-------
Ui
COMBINED SEWER
STORM OVERFLOW
SAMPLE
TO INDIVIDUAL OR
, COMPOSITE SAMPLE
30TTLE
COMBINED SEWER
STORM OVERFLOW
SAMPLE
RETURN SPRING
DIAPHRAM PUMP
RETURN TO
SEWER
COMBINED SEWER
STORM OVERFLOW
SAMPLE
NORMAL FLOW
AUTOMATIC SAMPLER
SAMPLE AOUISITION
Figure 14. Rohrer Automatic Sampler
Taken from EPA Report No. 11022 ECV 09/71
-------
General Comments: The pump produces a continuous flow
of sewage through the sampling
header pipe and back to the sewer.
Two taps are provided to allow con-
tinuous flow through diversion
nozzles for the individual and com-
posite sample collection stations
and return to sewer. When it is
desired to collect a sample, a
solenoid is actuated operating a
linkage which mechanically rotates
the diversion nozzle causing the
flow to enter a chamber connected
to the sample bottle rather than
the sewer return. A spring assures
return of the diversion nozzle to
its original position after the
sample is taken. The time of sole-
noid activation governs the size
of the sample. The 24 discrete
sample bottles are mounted on a
turntable which indexes upon each
sampling cycle to place an empty
bottle under the filling spout.
Rohrer Automatic Sampler Evaluation
1. Should be relatively free from clogging.
2. Unit would not appear to offer any significant obstruc-
tion to flow.
3. Unit should be operable over the full range of flow
conditions.
4. Movement of solids in the flow should not hamper
operations.
5. Automatic operation. Continuous flow serves a self
cleaning function.
6. Collects 24 discrete samples at pre-set time intervals
and a flow proportional composite.
7. Ability to collect floatables and coarser bottom
solids will depend upon details of sampling intake.
8. No refrigeration, but otherwise unit would appear to
afford reasonable sample protection.
166
-------
9. Unit was not designed for manhole operation.
10. Unit cannot withstand total immersion.
11. Unit would appear capable of operation in freezing
ambients.
12. Relatively high lift should allow operation over a
fairly wide range of operating head conditions.
167
-------
Des ignation;
Project Location:
EPA Report No.;
Sampler Intake:
Gathering Method:
Sample Lift;
Line Size;
Sample Flow Rate
Sample Capacity:
Controls:
Power Source:
Sample Refrigerator:
Construction Materials
Basic Dimensions:
WESTON AUTOMATIC SAMPLER
Washington, B.C.
11024 EXF 08/70
Details of intake to submersible
sewage pump and of sampling head
to vacuum-charged sampler not
stated.
Forced flow to a retention tank
by a sewage pump anchored to the
sewer floor, thence, by vacuum,
from the retention tank to sample
bottles.
Not stated.
Not stated.
Not stated.
Collects 24 discrete samples.
Wastewater is pumped continuously
to the retention tank. The vacuum
tank is triggered by the increased
back-pressure of a bubbler line
resulting from the increased depth
of sewer flow. The discrete in-
terval is adjusted by an electric
timer to a minimum period of
5 minutes.
115V ac
Sample bottles, sampling lines,
and control switches installed in
a refrigerated enclosure.
Not stated.
The wastewater retention tank, the
refrigerated sampler, and the
piping are all housed in a 7'
x 5'3" x 6'6" metal shed.
168
-------
FIGURE 0.1
MONITORING EQUIPMENT
Cl IEUISE SUTION
SUPEE COEEECIIOH IIHIOI
SIIPLIMC LUES-s,
:i CONDUCTOR
IICIETEO CJIIE
IISIEIIIE.il • III IIIE
• nrnioi IKK-, • PUU SIIICHES^ HI [^—|
IISI(IIH« (in LCI mrm LIII
— — i
EUCIRICHt HIE
& = 111::ime cnnouii m
IUIBLER EINE
D-l
Figure 15. Weston Automatic Sampler
Taken from EPA Report No. 11024 EXF 08120.
-------
General Comments:
A submersible, heavy-duty manually-
controlled sewage pump delivers
wastewater continuously to a reten-
tion tank having a normal retention
time of less than 1 minute. The
pump is anchored to the sewer bottom
in a metal cage.
During a storm, an increase of
water depth in the sewer applies
back pressure to an air-bubbling
system, thus activating a mercury
switch and triggering the system
which collects samples from the
retention tank. The 24 sample
bottles are vacuum charged prior
to the storm by use of a portable
vacuum pump. The bottles are in a
fixed position in the refrigerated
enclosure, and each sample is drawn
into its bottle by vacuum when a
control switch is released by a
tripper arm operated in conjunction
with a timer.
Weston Automatic Sampler Evaluation
1. The submersible pump anchored to the bottom of the
sewer is often clogged by solid wastes such as cans,
rags, wire, wood chips, tree stems, gravel, sand, etc
2. The submersible pump with its metal cage and angle
iron braces offers a significant obstruction to flow.
3. Pump stoppages have occurred during low-intensity
storms, probably because of insufficient water depth
in the sewer.
4. Movement of heavy solids has caused severe damage to
the equipment, to the extent that pumps have washed
away .
5. Automatic operation of sampler above retention tank.
Continuous flow from pump to retention tank assists
in self cleaning.
6. Collects 24 discrete samples at preset time intervals
Synchronized recorded flow data permit flow propor-
tional compositing. Samples are collected from a
single elevation in the sewer.
170
-------
7. Ability of unit to collect floatables or coarser
bottom solids will depend upon elevation of pump
intake.
8. Refrigerated sample container protects samples from
damage and deterioration. Continuous flow from sewer
to retention tank will help minimize cross-
contamination. Sampling head and lines may be
susceptible to precontamination.
9. Unit was not designed for manhole operation.
10. Unit cannot operate under a condition of total
immersion.
11. Not suitable for operation under freezing ambient
conditions. Could be made to operate during freezing
weather by heating the metal shed housing the unit.
12. Relatively high discharge pressure would allow
operation over a wide range of operating head
conditions.
171
-------
Designation:
Project Location
EPA Project No.:
Sampler Intake;
PAVIA-BYRNE AUTOMATIC SAMPLER
Gathering Method
S ample Lift;
Line Size:
Sample Flow Rate
Sample Capacity:
Controls:
Power Source:
New Orleans
Louisiana
(Lake Pontchartrain),
11020 FAS. Final report should be
available about June 1973.
Saran wrapped, galvanized sheet
metal air diffuser about 2 1/2'
long, placed about 8" below the
water surface. Polyethylene tubing
from intake to sampler.
Positive displacement, screw type,
Moyno or Aberdenffer pump operated
with a 3/4 HP motor.
Maximum suction
20 feet.
lift about
Minimum 3/4" line from canal to
sampler. Intake pipe to sampler
manifold 3/4". Manifold to each
row of sampler bottles, 1/2".
Line from solenoid valve to sampler,
1/4".
2 to 3 gallons per minute.
Unit collects 36 discrete samples
in bottles of about 40 ounce
capacity each.
Sampler operation initiated with
manually operated switch. Filling
of sample bottles controlled by a
motor driven timer, through relays,
to a solenoid valve at each sample
bottle. Time interval between
sample collections not stated.
Sample pump operates through a
220 volt, 60 cycle, external power
source. Electrical control equip-
ment is on a 120 volt, 60 cycle,
power source.
172
-------
Sample Refrigerator:
Construction Materials
Basic Dimensions:
Sample bottles, solenoid valves to
each bottle, and sampler manifold,
are installed in a Shaefer Cooler
Model MC-1600, with cooling units
built in its walls.
Sampler piping and fittings are of
PVC. Grating and supports within
the cooler are aluminum.
Outside dimensions of cooler in
which sampler is installed are
about 31" x 61" x 35". All
equipment is installed in a
6' x 8' shed.
General Comments:
The pump produces a continuous
flow of sewage to the sampler.
When the sampler has been placed
in operation, individual solenoid
valves from the sampler manifold
are opened one at a time to the
36 sample bottles by an electri-
cally operated timer. A combina-
tion standpipe and overflow line
is used to maintain pressure on the
solenoid valves.
Pavia-Byrne Automatic Sampler Evaluation
1. Most clogging would be at the air diffuser inlet. Its
extent would depend on the size and shape of openings
in the diffuser.
2. The air diffuser intake would present some obstruction
of flow, depending on where it is placed in the sewer.
This would not be significant in the very large canal
where the existing samplers have been installed.
3. Probably would operate at the full range of flow
conditions, except at very low stages, when the air
diffuser may not provide satisfactory inlet conditions,
4. Damage to the air diffuser intake may occur in storm
or combined sewers of high flow velocity and heavy
debris load.
5. Operation is automatic after initial startup at the
beginning of a storm. Continuous flow promotes self
cleaning.
173
-------
6. Representativeness of sample depends on placement and
configuration of the air diffuser intake. Discrete
samples of uniform size collected at constant time
intervals. Flow proportional compositing not possible
unless time-synchronized with a recording flow meter.
7. Does not collect floatable material because the intake
is set below the water surface.
8. Cooled sample container protects samples from damage
and deterioration. Continuous flow from sewer to
sampler minimizes precontamination.
9. Unit was not designed for manhole operation.
10. Not designed to operate under total immersion or
flooding.
11. Continuous flow and insulated cooler would help permit
continued operation under ambient freezing.
12. Relatively high lift would allow operation over a
fairly wide range of operating head conditions.
174
-------
Designation;
Project Location:
EPA Proj ect No. :
Sampler Intake:
Gathering Method;
Sample Lift:
Line Size;
Sample Flow Rate
Sample Capacity:
Controls:
Power Source:
Sample Refrigerator;
Construction Materials
Basic Dimensions:
General Comments:
REX CHAINBELT, INC. AUTOMATIC
SAMPLER
Kenosha, Wisconsin
11023 EKC. Final report should be
available about July 1973.
Pipe drilled with 1/4" to 3/8"
holes.
Uses a "Hushpuppy" positive pres-
sure pump. Cost of pump about $30.
Operates only during a 2-3 minute
purging period and during actual
filling of sample bottle.
Suction lift about 15 feet.
One-half inch Tygon tubing and
garden hose.
Approximately 3 gpm.
Unit collects 18 discrete samples
in bottles of 1-liter capacity.
Sampler operation started by manu-
ally operated control. Thereafter,
flow to sample bottles is regulated
by an electric timer and solenoid
valve. Time interval between
filling of bottles can be adjusted
between 3 minutes and 1 hour.
Not stated.
None provided.
Sampling lines are composed of
Tygon tubing and garden hose;
pump is plastic and Buna N.
Not stated.
After manual starting, the pump
runs for 2 to 3 minutes to purge
the sampler lines. The pump then
operates only while each sample
175
-------
bottle is filled through a re-
volving solenoid valve regulated
by an electric timer. Apparently,
the pump operation is stopped
automatically after 18 sample
bottles have been filled.
Rex Chainbelt Automatic Sampler Evaluation
1. Experience has been only in sewage which has been
comminuted and passed through a grit chamber, but
unit should be fairly free from clogging.
2. The pipe sampler intake would present some obstruction
of flow, the extent of obstruction depending on the
method used for maintaining the position of the pipe
in the flow.
3. Does not collect enough samples at short time inter-
vals to include the entire storm period at many
locations.
4. Operation impediment by the movement of solids will
depend on the method used for installation of the
sampler intake pipe.
5. Operation is automatic after initial startup at the
beginning of a storm. Self cleaning limited to
initial purging of lines .
6. Representativeness of sample depends on placement,
and specifications of the intake pipe. Discrete
samples of uniform size are collected at constant
time intervals. Flow proportional compositing not
possible unless time-synchronized with a recording
flow meter.
7. Unit could provide some capability for floatables and
bottom solids depending upon positioning and length
of sampler pipe.
8. No provision for refrigeration of samples provided.
Purging of lines prior to sample collection serves to
reduce precontamination; cross-contamination will
probably occur.
9. Unit was not designed for manhole operation.
176
-------
10. Not designed to operate under total immersion or
flooding.
11. Unit not designed to operate under freezing conditions.
12. Relatively high lift would allow operation over a
fairly wide range of operating head conditions.
177
-------
Designation:
Project Location
EPA Proj ect No. :
Sampler Intake:
Gathering Method
S ample Lift:
Line Size:
COLSTON AUTOMATIC SAMPLER
Durham, North Carolina
11030 HJP. Final report should
be available about July 1973.
Direct intake to sump pump set on
piling at stream bed. Intake
from sampling flume is a standard
Serco Model NW-3 sampling head.
Water pumped from stream to sam-
pling flume with an Ento-Cornell
sump pump, Model No. 150A. Pump
is placed inside a 2' x 1'6" metal
box, all within a woven wire frame.
A standard Serco Model NW-3 vacuum
sampler gathers samples from the
3' x 10 1/2" x 3/4" Plexiglas flume
About 11 feet from the pump to
the sampling flume. No lift from
the flume to the Serco sampler.
Line from pump to
fire hose. Serco
1/4" I.D.
flume is 1 1/2"
sampler lines are
Sample Flow Rate :
Sample Capacity:
Controls :
Power Source:
Sample Refrigerator
Flow rate from
about 50 gpm.
flume to Serco
pump to flume is
Flow rate from
sampler is variable
Twenty-four 500-ml bottles are pro-
vided in the Serco sampler. Actual
sample sizes are about 400 ml.
Operation of pump starts and stops
when float in an offstream stil-
ling well reaches specified stages
For Serco Model
trols, see
specified stages
NW-3 sampler con-
page 118.
Pump operates on 110V ac. Serco
sampler is powered with a spring
driven clock.
None provided.
178
-------
Construction Materials; Sampling train composed of fire
hose, Plexiglas flume, stainless
steel sampling head, vinyl lines,
and glass bottles with rubber
stoppers.
Basic Dimensions; Not a concentrated unit. Serco
sampler; 15 1/2"W x 15 1/2"D
x 26 3/4"H.
Colston Automatic Sampler Evaluation
1. Because of large diameter hose from the pump to the
sampling flume, and continuous flow during the period
of operation, clogging is infrequent. Experience has
been in an urban stream which has the characteristics
of a storm sewer.
2. The pump and covering, as placed on the stream bed,
would create a significant obstruction to flow,
particularly in a sewer of ordinary dimensions.
3. May not operate during very low flows, depending upon
height of pump inlet above stream bed.
4. Heavy bed loads could render the pump inoperable.
5- Pump starts and stops automatically in accordance
with specified water stages. Continuous flow to
sampling flume provides self cleaning, but the Serco
sampler has no self cleaning features.
6. Collects discrete samples at preset times from a
fixed point intake only. Flow proportional
compositing is possible when time is synchronized
with recording flow measurement equipment.
7. Unsuitable for collection of samples of floatables
or coarser bottom solids.
8. No refrigeration provided. Use of individual sam-
pling lines in the Serco sampler eliminates cross-
contamination possibility.
9. Not designed for operation in sewer manholes or
other confined spaces.
10. Not operable under conditions of total immersion or
flooding.
179
-------
11. Would not operate under freezing conditions.
12. Sample lift of about eleven feet to the sampling
flume, and a potential lift of 8 to 10 feet for the
Serco sampler, indicates capability for operation
under a fairly wide range of operating head
conditions.
180
-------
Designation;
Project Location:
EPA Report No.:
Sampler Intake:
Gathering Method:
Sample Lift;
Line Size:
Sample Flow Rate
Sample Capacity:
Controls:
Power Source:
Sample Refrigerator:
Construction Materials
Basic Dimensions:
ROHRER AUTOMATIC SAMPLER MODEL II
To be used in Akron, Ohio
N one
Not clearly stated but presumably
the end of the 2" I.D. suction line
mounted directly in the flow stream
to be sampled.
Suction lift from diaphram pump.
Not stated but probably good for
at least 20 feet.
3/4" I.D.
Depends
20 gpm.
upon lift; could exceed
Unit collects twenty-four
1/2-gallon discrete samples plus
a 5-gallon composite.
Has a provision for automatic
starting. Discrete samples and
composite aliquots can be collected
every 5 minutes paced by a built-
in timer adjustable from 5 to
60 minutes. Switches automatically
stop diversion to composite bottle
when it is full and shut sampler
off when last discrete bottle has
been filled.
115V ac
None
Tygon and PVC tubing; aluminum
diverter, nozzle, etc.; "Nalgene"
sample bottles; aluminum frame.
54"W x 30"D x 59"H including
mounting dolly. Can be wheeled
about, but appears too heavy to
lift without assistance.
181
-------
General Comments; The pump produces a continuous
flow of sewage through the sam-
pler diverter and back to the
sewer. Two solenoids are pro-
vided to allow diversion of flow
to either the discrete or com-
posite sample container for a
preset time period. They tip a
nozzle inside a diversion chamber
and thus direct the flow as com-
manded by the timing cams. The
nozzle is spring loaded to return
to its null position which directs
flow back to the sewer. A rotat-
ing nozzle is indexed over one of
24 funnels, each connected by a
piece of 3/4" I.D. tygon tubing to
one of the wide mouth discrete
sample bottles which are in a
rectangular array.
Rohrer Automatic Sampler Model II Evaluation
1. Should be relatively free from clogging, except per-
haps the tubes connecting the distribution funnels to
the discrete sample bottles.
2. Unit would not appear to offer any significant obstruc-
tion to flow.
3. Units should be operable over the full range of flow
conditions.
4. Movement of solids in the flow should not hamper
operations, except for possible diaphram wear.
5. Capable of automatic operation. Continuous flow
serves a self cleaning function.
6. Collects 24 discrete samples at preset time intervals
and a simple composite.
7. Ability to collect floatables and coarser bottom
solids will depend upon details of sampling intake.
8. No refrigeration, but otherwise unit would appear to
afford reasonable sample protection.
9. Unit was not designed for manhole operation.
182
-------
10. Unit cannot withstand total immersion.
11. Unit would appear capable of operation in freezing
ambients.
12. Relatively high lift should allow operation over a
fairly wide range of operating head conditions.
183
-------
Designation;
Project Location
EPA Report No.:
Sampler Intake:
Gathering Method
S ample Lift:
Line Size:
Sample Flow Rate
Sample Capacity:
Controls:
NEAR SEWER SAMPLER
Tested at San Jose Water Pollution
Control Plant.
None. Not developed under EPA
sponsorship.
Small hole (approximately 1/2"
diameter) in the side of a travers-
ing pick-up tube.
Mechanical; pick-up tube with
piston is lowered and fills
through intake near its lower end
as it traverses the stream to be
sampled. Sample is ejected
through a hole near the top of the
tube by raising the piston inside
the tube.
Will depend upon pick-up tube
length; 6-8 feet would appear to
be a practical maximum.
Smallest line (possibly 1/2")
would appear to be the one con-
necting the sample bottle to the
pick-up tube outlet.
Not applicable.
Developer simply states that
either a composite sample or a
number of discrete samples can
be provided.
An upper piston was added to allow
varying the quantity of samples
gathered during the stream depth
traverse in a controlled way. It
is activated by a water surface
sensor located on the bottom of
the pick-up tube. The water
sensor provides the capability
(in conjunction with a small
memory and logic unit) of gather-
ing flow-proportional samples, at
least to the extent that flow is
184
-------
CD
Ul
Figure 16. NEAR Sewer Sampler
Photograph courtesy of Nielson Engineering and Research, Inc
-------
Power Source:
Sample Refrigerator:
Construction Materials
Basic Dimensions:
General Comments:
proportional to water depth.
Otherwise samples could be paced
by a timer or arranged to accept
signals from an external flowmeter.
Basic unit could be battery
powered. External controls could
require alternating current.
None
Stainless steel and plastic.
Will depend upon length of pick-
up tube; say approximately 1'W
x I'D x 8'H plus a sample container
rack. Unit must be mounted in
manhole or otherwise near the flow
stream. Basic unit would appear
to weigh 30-40 pounds.
Sampler is out of the main flow
except when taking a sample.
Developer claims sampler can pick-
up a representative sample of
surface oil film. Both an initial
model and an improved prototype
have been fabricated and tested to
demonstrate the basic concepts
involved, but the unit has not
been made commercially available
as yet. A patent application has
been filed on the sampler and its
concept. Any requests for further
information should be directed to:
S. B. Spangler, Vice President
Nielsen Engineering & Research,
Inc .
850 Maude Avenue
Mountain View, California 94040
Telephone (415) 968-9457
NEAR Sewer Sampler Evaluation
1. Pick-up tube might collect debris (rags, paper, etc.)
during traverse which could clog inlet port; otherwise
should be relatively free from clogging.
186
-------
2. Pick-up tube offers a rigid obstruction to flow while
sample is actually being collected.
3. Unit would appear vulnerable to damage due to Strouhal
vibration at high flow rates.
4. Movement of large objects in the flow at the time a
sample is being taken could damage or even physically
destroy the pick-up tube assembly.
5. Prototype does not have an automatic start feature.
No self cleaning. Cross contamination appears very
likely.
6. Prototype is amenable to several types of control
systems, but none has been demonstrated as yet.
7. Preliminary test results indicate a capability of
collecting surface oil films. Unit is unsuitable
for collecting coarse bottom solids.
8. Sample container case not designed. Since unit
mounts in manhole near flow surface, samples are
vulnearable, and refrigeration does not appear
reasonable.
9. Unit is designed for manhole operation.
10. Unit cannot withstand total immersion.
11. Unit would appear to have difficulty operating in
freezing ambients.
12. Unit has design capability of operating over a fairly
wide range of operating head conditions.
187
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Designation;
Project Location
EPA Report No.:
Sampler Intake;
Gathering Method
Sample Lift;
Line Size;
Sample Flow Rate
Sample Capacity;
Controls:
Power Source;
Sample Refrigerator;
Construction Materials
FREEMAN AUTOMATIC SAMPLER
Columbia, Maryland
None
Provided by user.
External head to provide flow to
sampling equipment shed. Fluidic
diverters are controlled by sole-
noid valves by timer signals and
divert flow to discrete sample
containers, the flow otherwise
returning to waste.
Not applicable.
The smallest passage in the sam-
pling train is the 1/4" x 1/4"
throat of the diverter.
1.5 gpm.
Modularized construction allows
as many 1 quart discrete sample
containers to be used as desired.
For this installation, 6 modules
were arranged vertically in a
single cascade, and two cascades
were employed.
Timer-actuated solenoid valves
open and close the diverter con-
trol ports causing a sample to be
taken at preset time intervals.
Volume of sample is adjusted by
positioning the vent tube in the
sample jar.
110V ac
None
PVC pipe, fluidic diverters molded
from PVC, sample containers are
glass Mason jars, metal and ply-
wood frame.
188
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Divertcr Control Ports
Divcrter
Inlet
Fluidic Diverter
Valve
Standpipe
Mason Jar
Bypass Diverter
Outlet
Bottle Fill
Diverter Outlet
Bottle Fill
Fitting
Bottle Vent
Tube
Shelf
Sample Flow Out
Figure 17. Freeman Automatic Sampler Module
Sketch courtesy of Peter A. Freeman Associates, Inc.
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Basic Dimensions: Each 6 module cascade appears
to be about 1 1/2'W x I'D x 5'H.
Minimum height of a module is
6" head required for diverter
operation plus sample bottle
height.
General Comments; The complete absence of moving
parts in the flow stream is a
distinct advantage. With the use
of a bias orifice in one control
port, only one control line need
be blocked to obtain diversion.
The possibility of using such an
arrangement with the control lines
sequenced vertically in a timing
jar that is fed fluid by a cali-
brated wick would allow a sampler
with absolutely no moving parts
and requiring no power other than
from the fluid flow itself.
Freeman Automatic Sa.mj3le;r ^Evaluation
1. Should be free from clogging. Sampling intake must be
designed by user.
2. Sampler itself offers no flow obstruction.
3. Should operate well over entire range of flow
conditions .
4. Movement of solids should not hamper operation.
5. Continuous flow serves a self cleaning function. No
cross-contamination.
6. Collects adjustable size (up to 1 quart) discrete
samples at preset time intervals.
7. Ability to collect samples of floatables and coarser
bottom solids will depend upon design of sampling
intake.
8. No refrigerator. Adequate sample protection for this
installation.
9. Not designed for manhole operation as presently
configured.
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10. Cannot withstand total immersion.
11. Unit should be able to operate in freezing ambients.
12. Operating head is provided by user.
191
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SECTION VIII
EXPERIENCE WITH COMBINED SEWER SAMPLERS
In order to assess the efficacy of both standard commer-
cially available samplers and custom engineered units in
actual field use, a survey of recent EPA projects in the
storm and combined sewer pollution control area was con-
ducted. Final reports were obtained where available, but
for some projects only interim reports existed and, in a
few instances, telephone conversations had to be relied on.
In each project, the research and development contract or
grant was for an activity which also required determination
of water quality. No projects have been undertaken solely
to compare or evaluate samplers for use in storm and com-
bined sewers.
STRAINER/FILTER TREATMENT OF COMBINED SEWER OVERFLOWS
Reference 8 is the final report for a project to examine
strainer/filter treatment of combined sewer overflows.
Although automatic sampling equipment was not used in this
project, several interesting observations were made. It is
stated in the conclusions that "this feasibility study has
shown that sampling methods commonly used in evaluating the
effect of combined sewer overflows on receiving streams
cannot be considered reliable. The results indicate that
most of the calculated loads that are based on automatic
sampling stations have most likely understated the actual
case". Particular criticism is leveled against the small
diameter, low velocity probes which are characteristic of
most present-day automatic sampling units. In this project
the sampling was performed manually by a technician at the
overflow site. Samples were taken at 15-minute intervals
during the first 2 hours of flow and thereafter at
30-minute intervals for 2 hours. The samples were discrete
in nature, not composits over each time interval, and were
taken in two quantities: a) 2-gallon sample taken with
a 1-gallon pail, and b) a 1-gallon sample taken with a
1-pint wide-mouth cup. The samples were brought to the
analytical laboratory within 6 hours of the initial
sampling time.
It is noted on page 18 that visual observation of several
overflows conclusively showed the presence of fresh human
feces (larger than one-half inch) and whole pieces of toilet
paper. Samples were also collected using a wire mesh screen
with one-quarter inch openings . Comparison of the suspended
solids in the usual pail samples with those collected on
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wire mesh strainers consistently showed a variation in par-
ticle size. Only when a sample was taken at the surface
of the flowing stream did the maximum particle size obtained
with the pail equal that found with the wire mesh strainer.
In one instance a set of samples was taken by two people
simultaneously at the same surface depth. The pail sample
was found to have consistently higher values than the scoop
sample for each variable tested. These variables included
BOD, COD, suspended solids, total solids, volatile solids
and settleable solids. In some instances the analyses of
the scoop obtained samples resulted in values less than
half of those obtained from pail collected samples.
Although whole sections of toilet paper were noted in the
overflow, the sampling technique used did not produce or
yield any paper in the samples. Since a double sheet of
toilet tissue weighs approximately 0.37 grams and would
yield a COD value of approximately 19,400 mg/1, the impact
on analytical results is obvious.
STREAM POLLUTION ABATEMENT FROM COMBINED SEWER OVERFLOWS
Reference 9 contains the results of a detailed engineering
investigation and comprehensive technical study to evaluate
the pollution effects from combined sewer overflows on the
Sandusky River at Bucyrus, Ohio. The overflows from many
storms were sampled during the study period to determine
the quality of the overflow and pollution loads. For about
6 months samples were collected manually. After
February 1, 1969, Serco automatic samplers, Model NW-3,
were installed in the instrument shelters at the overflows.
These samplers collected a 300 ml sample every 5 minutes
for 2 hours during overflow. If the overflow continued
longer than 2 hours, samples were collected manually at
less frequent intervals .
It is noted on page 15 that an automatic starter was devised
for the samplers that started the clocks when the water
level reached a pre-determined height behind the weirs . The
samplers could therefore be left unattended prior to and
during an overflow. The samplers required a vacuum to be
maintained in the sample bottles. Because the samplers
would lose vacuum after 1 or 2 days, they had to be in-
stalled in the 24 hours preceeding the overflow.
Except for these comments regarding difficulty with auto-
matic starters and vacuum leaks, no other in-service related
problems were mentioned.
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CONTROL OF POLLUTION BY UNDERWATER STORAGE
Reference 10 contains the results of a demonstration proj-
ect for the control .of pollution by underwater storage. A
pilot plant was designed, constructed and operated to assess
the feasibility of providing a facility for the collection,
treatment, storage and final disposition of storm overflow
from a combined sewer system. A Serco Model NW-3 automatic
sampler was located at the Parshall Flume. It was found to
be inadequate for the requirements of the testing laborator-
ies. The sampling quantities required were four times
greater than that originally contemplated. As a result,
samples were taken partly with the automatic sampler, but
primarily by hand. No other comments of the suitability of
this sampler for its application or experience with it were
made .
ENGINEERING INVESTIGATION OF SEWER OVERFLOW PROBLEMS
Reference 11 contains the results of an engineering investi-
gation of sewer overflow problems in Roanoke, Virginia.
Both manual and automatically gathered samples were obtained
during storm events to assess the quality of sewer overflows
and storm runoff. Serco automatic samplers were used in
this program. The problems encountered during sampling
primarily involved the equipment. It is noted on page 149
that the automatic samplers worked rather well, except that
some precautions had to be taken. In the streams the nozzle
could not be rested on the bottom, or sand and grit would be
drawn in the sample bottle. Rags from the sanitary sewers
would block several of the tube openings during a 24-hour
sampling program. Occasionally a clock would stop and a
complete rainfall would be missed. The automatic starting
devices proved to be inadequate; therefore, the samplers
had to be started manually at the beginning of each rain-
fall which proved to be time-consuming.
MICROSTRAINING AND DISINFECTION OF COMBINED SEWER OVERFLOWS
Reference 12 contains the results of an investigation of
micros training and disinfection of combined sewer overflows.
On page 20 it is noted that composite samples of the raw and
strained water were extracted automatically by two N-Con
Surveyor model samplers and stored in refrigerated contain-
ers. The samplers were adjusted to withdraw portions of
the flows at a fixed rate every 6 minutes. The only com-
ments made about the sampling equipment were that composite
sampling is not so representative of variations within a
storm and discrete samples would be more desirable, and a
complaint about the low suction lift which restricted
operations.
195
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In Phase II of this project reported in (12a) automatic
vacuum-type discrete samplers (Serco Model SG-15) were used.
The samplers collected discrete 300 ml samples of influent
and effluent every 2 minutes. The data on organic content
and coliform from 14 storms were rendered useless due to
improper sterilization of the samplers in the field. Sam-
pler failures were noted but not discussed.
STORMWATER POLLUTION FROM URBAN LAND ACTIVITY
Reference 13 presents the results of an investigation of
the pollution concentrations and loads from storm water
runoff in an urban area of Tulsa, Oklahoma. Standard proce-
dures for manual sampling were used when baseline samples or
stormwater runoff samples were collected. The stationary
automatic sampling method was used when a time series of
samples was desired. The sampling apparatus employed was
unique and custom-designed for this project by the contrac-
tor. Five semi-stationary automatic sampling stations and
three portable automatic samplers were fabricated and used
in this project. The only problems noted were due to van-
dalism. Several of the semi-stationary sampling stations
were broken open and some of the equipment was damaged.
This caused important data losses on some watersheds.
RETENTION BASIN CONTROL OF COMBINED SEWER OVERFLOWS
Reference 14 contains an evaluation of the control of com-
bined sewer overflows by retention in an open basin in
Springfield, Illinois. It is interesting to note that the
instrumentation subcontract cost was $31K, while the sub-
contract for construction of the basin itself only cost
$77K. A rather large scale fixed installation, automatic
sampling system was designed for this project. Originally
4-inch diameter influent and effluent sampling lines were
used. Pumps took suction from the sampling lines and dis-
charged in the sampling tanks. A Trebler scoop-type sampler
was provided in each tank to take the samples. Samples of
equal volume were taken at 30-minute intervals with the
automatic samplers and composited over a 24-hour period.
The composite bottles were located in a refrigerator and
were kept under mechanical refrigeration at all times.
Problems were experienced with operation of the samplers
during early months of the operation. This was particularly
true of the influent sampler. The influent sampling line
was over 900 feet long. It was concluded that this 4-inch
diameter line was much too large for the size pump taking
suction from it and, as a result, considerable amounts of
196
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solids settled in the line. This provided a non-
representative sample of the influent. There were also
difficulties associated with the location of the influent
sampler probe. As a solution, the 4-inch influent sampling
line was replaced with a 1.5-inch diameter line. This pro-
vided better velocities in the line and minimized settling
of solids in it. A listing of maintenance items required
over a 1-year period of operation is given on page 31. It
is noted that there was one instance of repair on the flow-
meter, seven instances of influent sampling line repair,
one instance of effluent sampling pump repair, one instance
of influent sampler motor burnout and replacement, three
instances of repair for both pumps, and eight instances when
the influent sampling line needed to be unclogged.
CHEMICAL TREATMENT OF COMBINED SEWER OVERFLOWS
Reference 15 contains the results of a study of flocculant
treatment and disinfection of combined sewer overflows at
Grosse Point Woods, Michigan. It is noted on page 48 that
one of the most difficult problems was that of sampling.
Flow rates varied from 305 to 2,450 cubic feet per second.
Influent sewage depths varied from 2 to 17 feet with no dry
well available for positive head devices, and a representa-
tive effluent sample had to be obtained from an inaccessible
weir approximately 210 feet in length.
All main sampling lines in the final design were 2 inches
in diameter and flowed constantly during the sampling
period. Because of the importance of sampling, automatic
samplers were designed and constructed specifically for work
on this project. These samplers were designed to collect
adjustable grab samples from the continuously flowing 2-inch
pipe stream, composite them for various periods, and hold
them in a refrigerated compartment for periods up to about
3 hours. No discussion of problems encountered with these
sampling devices was given.
COMBINED SEWER TEMPORARY UNDERWATER STORAGE FACILITY
Reference 16 contains the results of a demonstration of the
feasibility of utilizing a temporary underwater storage
facility as a means of abating pollution resulting from
storm overflow from a combined sewer. Conclusion number 5
is especially interesting: "The samplers utilized on the
project are not recommended for the sampling of sewage from
combined sewers. A more advanced and efficient sampling
method should be developed for future programs." On page 32
it is noted that "the required volume per sample was
1,020 ml to perform all required analyses. The standard
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Serco Model NW-3 automatic sampler would collect approxi-
mately 330 ml of sample per bottle when operated with a
5 foot lift, and 26 inches mercury internal vacuum and
an atmospheric pressure of 30 inches mercury. Therefore,
it was necessary to fill four bottles at a time for ade-
quate sample volume". A newly designed and fabricated
tripper arm was installed on the Serco sampler. The
tripper arm simultaneously actuated four sampling line
switches. A 15-minute gearhead was utilized for the tests
to provide a sampling interval that would not overtax the
field laboratory beyond its capacity.
URBAN RUNOFF CHARACTERISTICS
Reference 17 is an interim report on investigations for
the refinement of a comprehensive EPA stormwater management
model in which urban runoff characteristics are to be de-
picted. As a part of this program, automatic equipment for
sequential sampling of water quality was installed for
five separate sewer locations in the Bloody Run Sewer Water
Shed in Cincinnatti, Ohio. N-Con Sentry Sequential Effluent
Samplers were used in this program. The large amount of
data given in the report indicates a generally satisfactory
collection of samples but no operational comments are given.
IN-SEWER FIXED SCREENING OF COMBINED SEWER OVERFLOWS
Reference 18 reports on a project to examine the feasibility
of in-sewer fixed screening of combined sewer overflows. As
a part of this effort, a field sampling and analysis program
supplemented with laboratory studies was conducted to char-
acterize combined sewage contributory to combined sewer
overflows, and to ascertain the removal of floatables and
solid materials that could be effected by the placement of
the screening devices in these systems. For this program
special sampling equipment and supporting structures were
designed and manufactured in order to assure representative
collection of combined sewage samples. The equipment con-
sisted of two types of samplers: a bulk liquid sampler and
a screening sampler. Both employed the same support struc-
ture and the same sampling manhole. These are essentially
bulk grab samplers which allowed removal of an entire 1 foot
long section of combined sewage flow in the sewer. The
sampler is lowered by hand and raised by a winch. Samples
were collected on an hourly basis. No comments are made
about the operational experience with these samplers, but
apparently no difficulties were encountered.
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STORM AND COMBINED SEWER POLLUTION SOURCES AND ABATEMENT
Reference 19 is a report on a study of six urban drainage
basins within the city of Atlanta which were served by com-
bined and separated sewers. As a part of the effort to
determine the major pollution sources during storm events,
automatic sampling devices were used. The Serco Model NW-3
Sampling Device was used, but several difficulties are indi-
cated. On page 4 several interesting conclusions are noted:
"Samples collected by automatic sampling devices tended to
freeze in the sampling tubes during cold weather. Further-
more, the location of these vacuum operated devices at safe
heights above peak flow levels limited the volume of samples
that could be collected." "The automatic triggering device
utilized during this study was not reliable. Dampness
deteriorates electrical contacts and solenoids causing
failure of apparently well insulated parts. The consequent
necessity for manual triggering of the automatic samplers
reduces their usefulness and indicates the need for an im-
proved triggering device." "No significant differences
exist between water quality analyses of simultaneous samples
obtained by grab and automatic sampling techniques."
STORM WATER PROBLEMS AND CONTROL IN SANITARY SEWERS
Reference 20 is a report of an engineering investigation
which was conducted on stormwater infiltration into sani-
tary sewers and associated problems in the East Bay
Municipal Utility District with assistance from the cities
of Oakland and Berkeley, California. Grab samples were
collected with a rope and a bucket. Wet weather samples
were collected with an Edison Lever Action Diaphragm Pump
with a 1 1/2 inch suction line. Two types of portable
samplers were used for dry weather flow; the Hinde Effluent
Sampler which has a positive displacement pump with a
20-foot lift and an N-Con Surveyor automatic composite
sampler. The only real difficulty encountered in using
the automatic samplers was that the suction tubing was so
small that stringy and large size material tended to plug
the lines. This problem was circumvented by placing a
20-mesh galvanized wire fabric stilling well around the
ends of the suction tubes. Also it was not possible to
obtain samples automatically at one location because its
24 foot depth exceeding the lift capacity of the samplers.
It is noted on page 61 that the results of the analyses
which were conducted on the samples gathered with the auto-
matic sampling equipment were somewhate erratic.
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UNDERWATER STORAGE OF COMBINED SEWER OVERFLOWS
Reference 21 is a report of a demonstration study of off-
shore underwater temporary storage of storm overflow from
a combined sewer. It is interesting to note that one of
the recommendations given on page 3 is that, "collection
of grab samples of all flows should be used liberally to
confirm results from automatic samplers." The sampling
program included grab samples for the dry weather flow,
individually timed samples and composite samples of the
storm overflow from the combined sewer drainage area,
composite samples of effluent from the storage tanks, and
grab samples of bay water at the outfall. At the time of
design no sampler was commercially available to do the re-
quired job and at the same time secure a representative
composite sample. Therefore a sampler was designed and
constructed especially for this program. No operational
data regarding this sampler are given but apparently no
great difficulties were encountered.
MAXIMIZING STORAGE IN COMBINED SEWER SYSTEMS
Reference 22 is a report on maximizing storage in combined
sewer systems in the municipality of Metropolitan Seattle.
Programmed automatic-refrigerated samplers were designed
and built as a part of the demonstration grant to simplify
the sample collection tasks. These were manufactured by
Sirco and were their Sewer-Test Vary-Sampler models. The
report notes that, "the connotation of the term 'automatic'
is somewhat deceiving; considerable manual effort is in-
volved in collecting samples, replacing bottles and testing
and repairing the various electrical components". Origi-
nally the samplers were supervised, maintained and serviced
by different personnel. On the newly designed samplers,
there was a 6-month period during which the samplers were
broken in and various parts changed or modified. A single
technician was assigned supervisory, service and maintenance
responsibility for each of the automatic samplers and, since
then, performance has been satisfactory.
A number of sampler problems were encountered including the
electrical system which was quite complicated, the wiring
which was difficult to maintain, instances of inadequate
fuses, and failures of timers, microswitch.es, relays and
reed switches. It is also noted that despite an automatic
purging feature, the 3/8-inch diameter sampling tubes often
became clogged with rags and other debris and required con-
stant checking. During periods of extremely high flows, the
sampler tubes were often flushed over emergency overflow
weirs and left hanging high and dry when the flow subsided.
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After the reporter's extensive history with the use of these
samplers, two of the conclusions were especially noteworthy;
"Samplers and recorders to be effective require regular surveil-
lance and maintenance. The smallest failures can reduce valu-
able data to a level that is unuseable for certain statistical
analyses." "The best sampling equipment is generally the least
complex, is portable, does not require lines, constrictions, or
bends, and is not likely to become damaged when submerged (a
large order)."
OTHER EPA PROJECTS
Among EPA projects surveyed for which final reports are not avail-
able is a project (EPA No. 11023 FAT) for the construction , opera-
tion and evaluation of a stormwater detention and chlorination
station to treat combined sewer overflows on the Charles River in
Boston, Massachusetts. Operation of the station commenced in
early summer of 1970. Two Pro-Tech, Inc., Discrete Flow Samplers,
Model DEL-240, are installed for obtaining discrete samples of
inflow to the plant. These can be adjusted to sample at various
time intervals from 1 minute to 24 hours. In a recent telephone
conversation with the engineer in charge of the facility, it was
learned that numerous troubles were experienced with the samplers
during early operation. After various adjustments and modifica-
tions by the maunfacturers the samplers operated satisfactorily.
The specific nature of the troubles experienced was not discussed,
but will be reported by letter.
In a project (EPA No. 11023 FAS) for the chlorination of a large
volume of stormwater draining to Lake Pontchartrain in Louisiana,
seven samplers were designed and constructed specifically for the
project. Difficulty was experienced with solenoid operation of
a brass valve. Apparently, satisfactory operation was attained
after redesigning the valve in PVC. Initially, a telephone tone
was used to start and stop the samplers. This method of actuation
did not prove to be satisfactory and was discontinued. Information
concerning these samplers was obtained by telephone conversation
with the project engineer.
In a project (EPA No. 14-12-24) for the demonstration of a meth-
od of treating municipal sewage with a device termed a "rotating
biological contactor", Serco automatic samplers were used for
sampling in the treatment plant. Apparently, under the control-
led plant conditions, performance of the sewer samplers was
satisfactory. A "rotating belt sampler", custom built for the
project, was used to sample wet weather flows
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to the plant. Samples were obtained "by means of a mechanical sam-
pler installed in a drop manhole in the street. A series of sampling
cups was driven along a belt to collect 250 ml samples about every
15 minutes during the combined flow. The sampler was actuated by
the flow measuring device and was stopped by a limit switch when the
first sample reached the drive system near the top of the manhole.
Records collected for the project show that the device operated on
18 days during periods of fairly small flow (under 10 cubic feet
per second).
In a grant project (EPA No. 11023 DXC) for the characterization and
treatment of combined sewer overflows in San Francisco, California,
a unique partially hand sampling device was used. A 12-inch pipe
core, set in pipe guides, is dropped to the bottom of the channel
with its cover open. Thus a partially integrated sample is forced
into the pipe. The cover is then closed and the sample is surfaced
by means of compressed air.
In a grant project (EPA No. 11020 FAX) to demonstrate system control
of combined sewer overflows in a large urban area, an automatic
sampler manufactured by Rock and Taylor of Birmingham, England, was
used. Megator Corporation, Pittsburgh, Pennsylvania, is distributor
of the sampler. It is of suction type with a maximum lift of 18 feet,
operating on a 12-volt battery or 120 volts, ac. Performance of this
sampler was continually troubled by blockage due to papers, rags, dis-
posable diapers, etc. Such troubles are described in project reports
during most months of operation. After a period of freezing during
the winter, use of the automatic sampler was discontinued, and hand
sampling was substituted.
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SECTION IX
STATE-OF-THE-ART ASSESSMENT
As can be noted from a review of the preceding sections,
despite the plethora of automatic liquid sampling equipment
that is available today, none is eminently suited for a
storm and/or combined sewer application. An assessment of
the current state-of-the-art from the technological view-
point is in order to indicate where and how improvements
can be made and to give design guides for the development
of new automatic samplers. The material is arranged in
subsections which deal with each of the basic sampler func-
tions, and the emphasis is on technical considerations to
assure satisfactory execution of each function. The func-
tions are interrelated, however, and the designer must use
a systems approach in his synthesis and analysis activities.
SAMPLER INTAKE ASSESSMENT
The sample intake of many commercially available automatic
liquid samplers is often only the end of a plastic suction
tube, and the user is left to his own ingenuity and devices
if he desires to do anything other than simply dangle the
tube in the stream to be sampled. In the following para-
graphs we wish to examine the functions of a sampler in-
take that is intended to be used in a storm or combined
sewer application and the design considerations that arise
therefrom.
Pollutant Variability
A general discussion of the character of storm and combined
sewage is given in section III where the variability of
pollutant concentration is also treated. We wish to con-
sider the latter factor here in somewhat more detail. Let
us consider first some empirical data from (23). In the
study, a special pressurized circulating loop was assembled
containing a 10-inch square test section some 15 feet long.
Careful measurements of the velocity contours were made and
near uniformity was observed. From figure 18, which shows
such velocity contours for a nominal 5 fps velocity flow,
it can be seen that the velocity one-half inch from the
wall exceeds 4.5 fps everywhere except near the corners.
Since the variability of a pollutant will be a function of
velocity variations (among other factors), it is of interest
to note the horizontal and vertical variations of sediment
distribution observed experimentally in this test section
with its very small velocity variation.
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SAMPLING POINTS
10
2 1012
INCHES FROM CENTER
CROSS SECTION OF CONDUIT -- VELOCITIES
SHOWN IN FT/SEC
Figure 18. Velocity Contours at Sampling Station*
* Taken from reference 23.
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Four readily available commercial sands, differing princi-
pally in size, were used in the study. They are referred
to by mean particle size (50 percent finer by weight) as
0.45 mm, 0.15 mm, 0.06 mm and 0.01 mm. Observed sediment
distribution for the three coarsest sands are indicated in
figure 19. For all practical purposes the 0.01 mm sand was
uniformly distributed. It should be noted here that the
vertical variation is probably enhanced due to the design
of the test loop, which would tend to enhance concentrations
of heavier particles to the outside (the bottom of the test
section in this case) due to the action of centrifugal
forces. Observations made in (7) indicate this effect
rather effectively. In their test set-up an 8-foot wide
flume was narrowed to an 18-inch test section by placing
an insert in the flume bed along the wall opposite to that
from which samples were to be extracted. Although the
reduction in width occurred some 36 feet upstream of the
sampler inlet, for the 0.45 mm sand used in the investi-
gation, concentrations at 1 inch from the wall were found
to be two to four times greater than at 3 inches from the
wall. Similar but less pronounced horizontal concentration
gradients were observed for the finer sands as well.
The observation was made in (7) that, in addition to
variations in sediment concentration within the cross-
section at a given time, the sediment concentration at any
point in the cross-section was highly variable with respect
to time, especially for the coarser sediments (0.45 mm).
This observation was also made in (23) where data are
presented on concentration variation with respect to time
as a function of sampling interval. The concentration of
successive 20-second samples was found to vary over a range
of 37 percent of the mean, and the concentration of succes-
sive 60-second samples varied over a range of 10.5 percent.
Such variations arise from the natural turbulence of the
flow as would be encountered in an actual sewer and from
the non-uniform nature of re-circulated flows in test loops
which is peculiar to laboratory simulations.
So far we have focused our attention on relatively heavy
(specific gravity approximately 2.65) solids and their dis-
tribution in a flow. For the lighter organic solids with
specific gravities near unity, the particle distribution
will be more nearly uniform in a turbulent flow. It would
appear that one can expect a reasonable degree of uniformity
in the distribution of particles which fall in the Stokes1
Law range of settling velocities, i.e., for values of the
external Reynolds' number less than unity. If one describes
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1.2
o
Q_
o
«=c
Q.
O
O
o;
LU
o:
o
a.
LU
Q
1 .0
0.9
0.8
C 0.7
10
A. HORIZONTAL DISTRIBUTION AT MID-DEPTH
21012
INCHES FROM CENTER
SEDIMENT STREAM
SIZE VELOCITY
o- 0.06 mm
A- 0.15 mm
X - 0.15 mm
D- 0.45 mm
5 ft/sec
5 ft/sec
3 ft/sec
5 ft/sec
B. VERTICAL DISTRIBUTION AT CENTER
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
RATTn CONCENTRATION AT POINT
CONCENTRATION AT CENTER
Figure 19. Sediment Distribution at Sampling Station*
* Taken from reference 23.
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a particle in terms of its hydraulic size W, defined as the
velocity of uniform fall in a fluid at rest, Stokes* Law can
be written as
W = gd2 (s.g.-l)/18v (1)
where d is mean particle diameter, s.g. is the specific
gravity of the particle material, v is the kinematic viscos-
ity of the fluid, and g is the acceleration of gravity. The
external Reynolds' number (so called because the linear
dimension upon which it is based is a particle dimension
rather than a flow dimension) can be expressed as
Re = Wd/v (2)
Combining equations (1) and (2) we can express the range of
validity of Stokes' Law as
Re = gd3 (s.g.-l)/18v2 < 1 (3)
If one considers water at 60°F as the fluid (v=1.217
-5 2
xlO ft /sec), a plot of equation (3) over the range of
interest is given in figure 20. Here it can be noted that,
within the range of Stokes' Law, the maximum particle diam-
eter for sand with a specific gravity of 2.65 is less than
0.1 mm while for organic particles with a specific gravity
of 1.05 it is about 0.3 mm.
Since the kinematic viscosity of water is temperature de-
pendent, the Stokes' Law particle diameter limit will also
be a function of temperature. A typical plot of this vari-
ation is given in figure 21 for sand with a specific grav-
ity of 2.65 and Re=l. Here it can be noted that a decrease
in water temperature from the upper eighties to the mid-
forties results in a 50 percent increase in the maximum
particle diameter.
Sampler Intake Functions
The operational function of a sampler intake is to reliably
allow gathering a representative sample from the flow stream
in question. Its reliability is measured in terms of free-
dom from plugging or clogging to the degree that sampler
operation is affected and invulnerability to physical damage
due to large objects in the flow. It is also desirable,
from the viewpoint of sewer operation, that the sampler in-
take offer a minimum obstruction to the flow in order to
help prevent blockage of the entire sewer pipe by lodged
debris, etc.
207
-------
o
00
Q
o:
UJ
i—
UJ
s:
-------
0.14
0.13
0.12
0.11
Q
uj 0.10
1
O
i—l
I—
cc
D.
0.09
0.08 -
_L
I
I
I
I
40 50 60 70 80
WATER TEMPERATURE (°F)
90
Figure 21. Effect of Temperature on
Maximum Particle Size
209
-------
Let us first consider the ability of the intake to gather a
representative sample of dense suspended solids in the sed-
iment range, say up to 0.5 mm with specific gravity of 2.65.
The results of a rather thorough examination of relatively
small diameter intake probes (1/4" and 1/8" I.D.) are given
in (23). The argument is developed that, for a nozzle
pointing directly into the flow, the most representative
sample of a fluid/suspended-solids mixture will be obtained
when the sampling velocity is equal to the flow velocity
at the sampling point. Using this as the reference criteria,
investigations were conducted to determine the effects of
a) deviations from the normal sampling rate, b) deviations
from the straight-into-flow position of the probe, c) devia-
tions in size and shape of the probe, and d) disturbance of
sample by nozzle appurtenances. The effect of the sampling
velocity on the representativeness of the sample is indi-
cated in figure 22 which presents the results for 0.45 mm
and 0.06 mm sand. For the latter size, which falls within
the Stokes' Law range, less than ±4 percent error in con-
centration was observed over sampling velocities ranging
from 0.4 to 4 times the stream velocity. For the 0.45 mm
particles, the error at a relative sampling rate of 0.4 was
+45 percent, and at a relative sampling rate of 4 the
error was -25 percent.
For probe orientations up to 20° to either side of head-on,
no appreciable errors in concentration were observed. Sim-
ilarly, introduction of 0.150- and 0.375-inch probes showed
comparatively little effect on the representativeness of
the sample. The probe inlet geometry, i.e., beveled in-
side, beveled outside, or rounded edge, also showed little
effect on the representativeness of the sample, when com-
pared to the standard probe. Finally, in instances where
a sampler body or other appurtenance exists, the probe
should be extended a short distance upstream if a represent-
ative sample is to be collected. In summary, it was found
that for any sampler intake facing into the stream, the
sampling rate is the primary factor to be controlled.
Tests were also run with the sampling intake probes in the
vertical position to determine the effect such an orienta-
tion had upon the representativeness of the sample. With
such intakes, the sample entering them must undergo a 90°
change of direction, and consequently there is a tendency
for segregation and loss of sediment to take place. Tests
were run with the standard probe, an orifice (1/4-inch diam-
eter) in the center of a 1- by 2-inch flat plate oriented
so that its longest dimension was in the direction of flow,
210
-------
10.0
3.0
c/o
0.3
O.I
0.2
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
2.0
3.0 4.0 5.0 6.0 7.0 8.0 9.O IO.O
INTAKE VELOCITY
FLOW VELOCITY
Figure 22. Effect of Sampling Velocity on Representativeness of
Suspended Solids*
* Data from reference 23.
-------
and with an orifice in a crowned (mushroom shaped) flat
plate 1 1/4 by 2 inches. The results all showed negative
errors in concentration, increasing with particle size and
increasing with intake velocities less than the stream rate
but nearly constant for intake velocities higher than the
stream rate.
Since the smallest errors were found for the orifices in the
flat and mushroom shaped plates (whose performances were
nearly identical for intake velocities greater than one-half
the stream velocity), it was decided to investigate the ef-
fect of lateral orientation, i.e., to rotate the plate 90°
so that it might represent an orifice in the side of a con-
duit rather than in the bottom. The results for 0.15 mm
sand are presented in figure 23. It can be noted that while
the side orientation caused greater errors (as was to be ex-
pected) , these errors approached the nearly constant error
of the 0° orientation as the relative sampling rate was in-
creased above unity.
The work reported in (7) was a laboratory investigation of
pumping sampler intakes. Nine basic intake configurations,
all representing an orifice of some type in the side wall
of the flume, were examined. They included 1/2-, 3/4-,
1- and 1 1/2-inch diameter holes with square edges,
3/4-inch diameter holes with 1/8- and 1/4-inch radii, 1/2-
by 1—inch ovals, one oriented vertically and the other
horizontally, and a 3/4-inch diameter hole with a 2 inch
wide shelf just under it. Sand sizes of 0.10 mm and
0.45 mm were used in the study.
Reference samples were taken with a probe located near the
wall and pointing into the direction of the flow. The ref-
erence sample intake velocity was equal to the stream veloc-
ity. The primary measurement was sampling efficiency, the
ratio of the sediment concentration in the test sample to
that of the reference sample computed for a point 1/2-inch
from the wall. The reference sample was taken just before
and just after the test sample was gathered. Although the
data exhibited considerable scatter, several conclusions
were drawn. With regard to the intake velocity, greater
than 3 fps is generally desirable and, for sands coarser
than 0.2 mm, an intake velocity equal to or greater than the
stream velocity is desirable. With regard to intake config-
uration, for intake velocities greater than about 3 fps the
sampling efficiencies showed little effect of size of intake
(range of 1/2" to 1 1/2" diameter), of rounding the intake
edges, or of shape and orientation of the axis of the oval
intake. Sampling efficiency was found to decrease with
increasing particle size above 0.10 mm for all intakes
212
-------
NJ
I-1
to
10.0
3.0
-------
tested. Finally, although the shelf intake showed somewhat
higher sampling efficiency for coarse particles and high
stream rates, its performance was very erratic over the
entire range of test parameters.
Similar observations were made in field tests with river
water samples at St. Paul and Dunning, Nebraska, reported
in (24). In addition to the "standard" intake which was
a flush mounted 1-inch pipe coupling, alternate intakes
included 1- by 2-inch and 1- by 9-inch nipples; a 1- by
9-inch nipple with a 1/8 inch thick steel plate 14 inches
high and 17 inches wide at its end; and a 1 inch street
elbow with a 1- by 2-inch nipple oriented down, into the
flow and up. It was concluded that the standard intake was
as good as any in terms of sampling efficiency and was
therefore preferable since it offered no obstruction to
the flow and was therefore less vulnerable to damage by
debris. The sediment being sampled was rather fine; in
high flows 88 percent was finer than 0.062 mm and 100 per-
cent was finer than 0.50 mm.
To summarize the foregoing as it relates to the sampler in-
take function of gathering a representative sample we note
the following:
1) It becomes difficult to obtain a one-to-one
representation, especially for inlets at 90°
to the flow, for large, heavy suspended
solids .
2) For particles that fall within the Stokes'
Law range, consistent, representative samples
can be obtained.
3) The geometry of the sampler intake has little
effect on the representativeness of the sample.
4) The sample intake velocity should equal or
exceed the velocity of the stream being
sampled.
Sampler Intake Design
The foregoing suggest certain directions that the design of
a sampler intake for storm and combined sewer flows should
take. At the outset, it appears unwise to attempt to sample
suspended solids that fall much outside the Stokes' Law
range. A realistic maximum size for sand with specific
gravity of 2.65 would appear to be around 0.1 mm to 0.2 mm.
High sample intake velocities will be required, perhaps in
excess of 10 fps, if the sample is to be representative.
214
-------
Although the flow may be nearly homogeneous, except for
very coarse solids and large floatables, more than one
sample intake is desirable for reliability of operation as
well as insurance against some unforeseen gradient in the
pollutant. In view of the changing water levels in the
conduit with changing flows, the changing velocity gradients
within the flows, and the possibility of changing pollutant
gradients not only with respect to these but also with type
of pollutant; not even a dynamically adaptive sampler in-
take can be designed to gather a sample that is completely
representative in every respect at the same time.
In order to better illustrate this point, let us consider
a round pipe of radius R containing a flow at depth d and
an arbitrary vertical concentration gradient of some
pollutant.
Locate the origin of a cartesian coordinate system at the
invert with the y axis positive upwards. We now assume
that the pollutant concentration gradient can be expressed
as a polynomial in y, i.e.,
p =E anyn <4>
n
The expression for the amount of pollutant in an arbitrary
cross-sectional zone (say between depths y, and y^) is
;2E
dy (5)
n y n
If one sets P=2-(P the first few terms are;
n
+ R2[sin~1(y2/R-l) - sin'1 (y^R-l)] 1
(6)
(7,
215
-------
f 5 2\3/2
2 (8)
3/2 5R PQ |
+ 8a I
o J
etc .
Using such a formulation one can obtain the values of y
which divide the flow cross-section up into some number of
zones each of which contains an equal amount of pollutant;
let us designate them as y,,y2>...»y • If one extracts a
sample from the center of each zone, one can argue that its
representativeness will be quite good, especially for large
values of m. Unless the samples extracted from each zone
are kept discrete, which would result in an inordinately
large number of samples, the quantity of sample gathered
from each inlet must be varied in accordance with the
velocity gradient if the composite sample is to be repre-
sentative in a mass transport sense. For a different
concentration gradient p , one will obtain new values
Y-i »yo > • • • >y and hence different port locations and
different quantities of sample required even for the same
flow depth.
In view of the over-riding design mandate that simplicity
maximizes probability of success, it becomes immediately
apparent that the equipment sophistication implied by the
foregoing would doom the design to operational failure if
such a course were to be attempted. In the absence of some
consideration arising from the particular installation site,
a regular distribution of sampling intakes across the flow,
each operating at the same velocity, would appear to suf-
fice. Since the intakes should be as non-invasive as possi-
ble in order to minimize the obstruction to the flow and
hence the possibility of sewer line blockage, it seems
desirable to locate them around the periphery of the
conduit.
GATHERING METHOD ASSESSMENT
As was noted earlier, three basic sample gathering methods
or categories were identified; mechanical, suction lift, and
forced flow. Several different commercial samplers using
each method are available today. The sample.lift require-
ments of the particular site often play a determining role
216
-------
in the gathering method to be employed. Some mechanical
units were specifically designed for lifts to 200 feet.
The penalty that one must trade-off in selecting a mechani-
cal gathering unit is principally the necessity for some
obstruction to the flow, at least while the sample is being
taken. The tendency for exposed mechanisms to foul, to-
gether with the added vulnerability of many moving parts,
means that successful operation will require regular,
periodic inspection, cleaning, and maintenance.
Forced flow from a submersible pump also necessarily results
in an obstruction to the flow. Pump malfunction and clog-
ging, especially in the smaller sizes often used in sam-
plers, remains a distinct possibility and, because of their
location in the flow stream itself, maintenance is more
difficult to perform than on above-ground or easily re-
movable units. Pneumatic ejection is employed by several
manufacturers, the gas source being either a compressor or
bottled refrigerant. The latter units must necessarily be
of small scale to avoid an enormous appetite for the re-
frigerant. The advantages of explosion-proof construction
and high lift capability must be weighed against low line
velocities, low sample intake velocities, and relatively
small sample capacities.
Suction lift units must be designed to operate in the envi-
ronment near the flow to be sampled or else their use is
limited to a little over 30 feet due to atmospheric pres-
sure. The necessity to have a pump that is free from clog-
ging has led some designers to use peristaltic tubing pumps.
Most of these operate at such low flow rates, however, that
the representativeness of suspended solids is questionable.
Newer high-capacity peristaltic pumps are now available and
should find application in larger automatic samplers. The
ability of some of these pumps to operate equally well in
either direction affords the capability to blow down lines
and help remove blockages. Also, they offer no obstruction
to the flow since the transport tubing need not be inter-
rupted by the pump, and strings, rags, cigarette filters
and the like are passed with ease. With all suction lift
devices a physical phenomenon must be borne in mind and
accounted for if sample representativeness is to be main-
tained. When the pressure on a liquid (such as sewage)
which contains dissolved gases is reduced, the gases will
tend to pass out of solution. In so doing they will rise
to the surface and entrain suspended solids in route. (In
fact, this mechanism is used to treat water; even small
units for aquariums are commercially available.) The
result of this is that the surface layer of the liquid
may be enhanced in suspended solids, and if this layer is
217
-------
a part of a small sample aliquot, the sample may not be at
all representative. In the absence of other mitigating
factors, the first flow of any suction lift sampler should
therefore be returned to waste.
All in all, the suction lift gathering method appears to
offer more advantages and flexibility than either of the
others. The limitation on sample lift can be overcome by
designing the pumping portion of the unit so that it can
be separated from the rest of the sampler and thus posi-
tioned not more than 30 feet above the flow to be sampled.
For the majority of sites, however, even this will not be
necessary.
SAMPLE TRANSPORT ASSESSMENT
The majority of the commercially available automatic sam-
plers have fairly small line sizes in the sampling train.
Such tubes, especially at 1/8-inch inside diameter and
smaller, are very vulnerable to plugging, clogging due to
the build-up of fats, etc. For application in a storm or
combined sewer, a better minimum line size would be 3/8- to
1/2-inch inside diameter.
It is imperative that adequate sample flow rate be main-
tained throughout the sampling train in order to effectively
transport the suspended solids. In horizontal runs the
velocity must exceed the scour velocity, while in vertical
runs the settling or fall velocity must be exceeded several
times to assure adequate transport of solids in the flow.
The complexities inherent in the study of a two-phase
mixture such as soil particles and water are such that
rigorous analytical solutions have not yet been obtained
except in certain limiting cases such as the work of Stokes
cited earlier. The use of hydraulic size, which is the
average rate of fall that a particle would finally attain
if falling alone in quiescent distilled water of infinite
extent, as a descriptor for a particle involves its volume,
shape and density. It is presently considered to be the
most significant measurement of particle size. However
there are no analytical relationships to allow its computa-
tion; recourse must be made to experiment. The geometric
size of a particle can be based upon its projected lengths
on a set of right cartesian coordinates oriented so that a
is its major axis, b is its intermediate axis, and c is its
minor axis. With patience and a microscope the lengths a,
b, and c of a particle can be determined. Since the number
218
-------
of particle shapes is infinite, a system for classification
is required. One put forth in (25) is the shape factor
defined as:
SF
= c/^/Ib (9)
which approximately defines the shape in terms of three of
a multitude of dimensions of an irregular particle. Of
course there may be rounded, angular, smooth and rough
particles all with the same shape factor.
An excellent discussion of the fundamentals of particle
size analysis is given in (26). Table 3, which is taken
from data presented therein, illustrates the effect of
shape factor on hydraulic size for sand particles with
specific gravity of 2.65 in water at 20°C. It can be noted
that while a sphere with a nominal diameter of 0.2 mm will
fall only about one-third faster than a similar sized par-
ticle with a shape factor of 0.3; a sphere with a nominal
diameter of 4.0 mm falls over 2 1/2 times faster than a
particle with SF=0.3. For curves showing temperature
effects, correction tables, etc., the reader is referred
to (26).
In the absence of better data, the hydraulic size of a
particle can be computed from the following (27);
W3/2 = gd3/2 (s.g.-l)/11.2V^" when KRe<30 nf)
0.1400
d> 2 mm
Equation (10) is Prandtl's formula for a smooth channel,
while equation (12) is the so-called square law.
The transport of solid particles by a fluid stream is an
exceedingly complex phenomena and no complete theory which
takes into account all of the parameters has yet been
formulated. Empirical formulae exist, however, some of
which have a fairly wide 'range of applicability. An ex-
pression for the lowest velocity at which solid particles
heavier than water still do not settle out onto the bottom
219
-------
TABLE 3. EFFECT OF SHAPE FACTOR ON HYDRAULIC
SIZE (IN CM/SEC)*
>T • i ™ • . Shape Factors
Nominal Diameter
(mm) 0.3 0.5 0.7 0.9 Spheres
0.20 1.78 1.94 2.11 2.26 2.43
0.50 4.90 5.63 6.31 7.02 7.68
1.00 8.49 10.10 12.10 14.00 15.60
2.00 12.50 15.50 19.30 23.90 28.60
4.00 17.80 22.40 28.00 35.60 46.90
* Taken from reference 26.
220
-------
of the pipe or channel has been developed by Knoroz (28)
on the basis of numerous experiments carried out under his
direction at the Ail-Union Scientific Research Institute
for Hydraulic Engineering. It expresses the velocity in
meters per second as;
where average values of d and W for the solids mixture are
to be used; R is the hydraulic radius; and p is the con-
sistency by weight of the mixture, i.e., in percent the
expression for p is:
Y™ ~ Y Y^
p=7LT-Y-r£ d4)
p m
where y is the specific weight of the fluid, y is the
specific weight of the particles, and y is the specific
weight of the mixture. For a review of this and other
Russian work on the flow of a two-phase mixture see (27).
A somewhat simpler expression for the adequate self-
cleaning velocity of sewers derived by Camp from experi-
mental findings of Shields as given in (29) is:
V =486 R1/6\/0.8d(s.g.-l) (15)
where f is the friction factor, n is Manning's roughness
coefficient, and all other terms are as previously identi-
fied. Using equation (15), for example, it is seen that a
velocity of 2 feet per second is required to adequately
transport a 0.09 mm particle with a specific gravity of 2.65
and a friction factor of 0.025. By comparison, the fall
velocity of such a particle is around 0.2 feet per second.
In summary, the sampling train must be sized so that the
smallest opening is large enough to give assurance that
plugging or clogging is unlikely in view of the material
being sampled. However it is not sufficient to simply make
all lines large, which also reduces friction losses, without
paying careful attention to the velocity of flow. For a
storm or combined sewer application, minimum line sizes of
3/8- to 1/2-inch inside diameter and minimum velocities of
2 to 3 feet per second would appear warranted".
221
-------
SAMPLE CAPACITY AND PROTECTION ASSESSMENT
For storm and combined sewer applications, discrete sampling
is generally desired. This allows characterization of the
sewage throughout the time history of the storm event. If
the samples are sufficiently large, manual compositing can
be performed based on flow records or some other suitable
weighting scheme. Although the quantity of sample required
will be a function of the subsequent analyses that are to
be performed, in general at least 1 quart and preferably
2 quarts will be desired. An additional benefit arises
because such relatively large samples are less vulnerable
to errors arising from cross-contamination.
A brief look at the different types of composite samples is
in order. Any scheme for collecting a composite sample is,
in effect, a method for mechanically integrating to obtain
average characteristics. Let us consider a given flow rate
q(t) and pollutant concentration level k(t) where:
q = L3!"1 and k = ML~3 (16)
The quantity of flow and pollutant are then:
Q = /qdt and P = /qkdt (17)
where:
Q = L3 and P = M (18)
Let us consider first the simple composite, where a constant
volume of fluid is added at evenly spaced time intervals.
We will denote such a sample by TV, meaning time interval
between successive aliquots constant and volume of aliquot
constant. Let the time duration of the event in question be
divided up into n elements and a subscript i be used to
denote instantaneous values (0
-------
integration given a fixed number of steps. One is to in-
crease the order of the integration scheme to be used; as
in going from the trapezoidal rule to Simpson's rule, for
instance. The other is to vary the step size in such a way
as to lengthen the steps when slopes are changing very
slowly and shorten them when slopes change rapidly. Typi-
cal of the first approach are the constant time interval,
variable volume (TV) proportional composites. There are
two straightforward ways of accomplishing this. One is to
let the aliquot volume be proportional to the instantaneous
flow rate, i.e.:
v± = Aq± (20)
and the other is to make the aliquot volume proportional to
the quantity of flow that has passed since extraction of the
last aliquot, i.e.:
Vi = B(Qi~Qi-l) = BAQi (21)
The respective concentrations of samples are
£«iki jSiki
KA , i=i and KB = i=i (22)
Typical of the second approach is the variable time interval,
constant volume (TV) proportional composite. Here a fixed
volume aliquot is taken each time an arbitrary quantity of
flow has passed (Q/n), i.e. the time is varied to give a
constant AQ. The concentration will be:
K = ^E k (23)
1=1
It must be remembered that here the time steps are differing
so that comparison of equations (23) and (19) has no meaning.
It is instructive to compare these four composite sample
schemes with each other. For the purposes of this exercise
let us arbitrarily set n=10 and normalize time so that
0
-------
These selections are completely arbitrary (except for
simplicity in exact integration), and the curious reader
may wish to examine more typical expressions. For a storm
event, the combination q = simrt and k=e allows for low
volume, highly polluted flow initially, with pollutant con-
centration falling throughout the event. However the re-
semblence is qualitative only, and more refined expressions
could be used. For each flow/concentration combination,
the exact average concentration of the flow was computed
(as though the entire flow stream were diverted into a
large tank for the duration of the event and then its con-
centration measured). The ratio of the composite sample
concentration to the actual concentration so computed is
presented in matrix form in table 4. The four lines in
each cell represent the four types of composite samples
discussed as indicated in the legend. The best overall
composite for the cases examined is the T V with the vol-
ume proportional to the instantaneous flow rate q. The
T V , where the volume is proportional to the flow since the
last sample, and the T V gave very similar results with
a slight edge to the former. However, the differences are
not large for any case. This brief look at compositing
merely scratches the surface, but a more definitive treat-
ment is outside the scope of the present effort. Suffice
it to say here that both flow records and a knowledge of
the temporal fluctuation of pollutants, as can be obtained
from discrete samples, are required in order to choose a
"best" compositing scheme for a given installation.
The sample container itself should either be easy to clean
or disposable. The cost of cleaning and sterilizing makes
disposable containers attractive, especially if bacterio-
logical analyses are to be performed. Although some of
today's better plastics are much lighter than glass and
can be autoclaved, they are not so easy to clean or in-
spect for cleanliness. Also the plastics will tend to
scratch more easily than glass and, consequently, cleaning
a well-used container can become quite a chore. The food
packaging industry, especially dairy products, offers a
wide assortment of potential disposable sample containers
in the larger sizes. Both the 1/2-gallon paper and plas-
tic milk cartons can be considered viable candidates, and
their cost in quantity is in the pennys-each range.
The requirements for samp.le preservation were enumerated
in section IV and will not be repeated here. It should
be mentioned, however, that if the samples are allowed to
become too cold, they may no longer be representative.
224
-------
TABLE 4. RATIO OF COMPOSITE SAMPLE CONCENTRATION TO
ACTUAL CONCENTRATION
>v CONG
q \.k
4 ^v
FLOW >v
1
c
;r t
\. 1-t
M^^te
/~\ sinirt
\
1-t
0.90
0.90
0.90
0.90
1.35
0.90
0.86
0.87
0.68
0.95
0.92
0.92
0.90
1.01
0.90
0.90
|^-
1 —
0.97
0.97
0.97
0.97
1.09
0.97
0.96
0.96
0.87
0.98
0.97
0.97
0.97
1.00
0.97
0.97
h
7ft
COS— r-
0.92
0.92
0.92
0.92
1.26
0.90
0.87
0.89
0.72
0.98
0.95
0.93
0.88-
1.00
0.92
0.92
-—
-t
e
0.95
0.95
0.95
0.95
1.14
0.97
0.95
0.95
0.82
0.96
0.95
0.95
0.97
1.00
0.95
0.95
K
sirnrt
0.99
0.99
0.99
0.99
0.99
0.90
0.89
0.97
0.99
1.12
1.09
0.97
0.80
1.01
0.98
0.97
Line 1.
Line 2.
Line 3.
Line 4.
T V
c c
T V
C V
T V
C V
T V
v c
Simple composite
Volume proportional to flow rate (q)
Volume proportional to flow (Q) since
last sample
Time varied to give constant AQ
225
-------
For example destruction of the organisms necessary for
the development of BOD may occur or freezing may cause
serious changes in the concentration of suspended solids .
Light can also affect samples and either a dark storage
area or opaque containers would seem desirable. Unless
disposable containers are used, however, it will be dif-
ficult to inspect an opaque container for cleanliness.
Again the paper milk carton is attractive since not only
is it relatively opaque, but its top opens completely
allowing visual inspection of its contents.
CONTROLS AND POWER ASSESSMENT
The control aspects of some commercial automatic samplers
have come under particular criticism as typified by comments
in section VIII. It is no simple matter, however, to pro-
vide great flexibility in operation of a unit while at the
same time avoiding all complexities in its control system.
The problem is not only one of component selection but
packaging as well. For instance, even though the possi-
bility of immersion may be extremely remote in a particular
installation, the corrosive highly-humid atmosphere which
will, in all liklihood, be present makes sealing of control
elements and electronics desirable in most instances.
The automatic sampler for storm and combined sewer appli-
cation will, in all liklihood, be used in an intermittent
mode; i.e. it will be idle for some period of time and
activated to capture a particular meteorological event.
If field experience to date is any indication, the greatest
need for an improved control element is for an automatic
starter. While the sensor is not a part of the sampler
proper, its proper function is essential to successful
sampler utilization. Although remote rain gages, etc. can
be used for sensing elements, one of the most attractive
techniques would be to use the liquid height (or its rate
of increase) to start a sampling cycle. This will avoid
the difficulties associated with different run-off times
due zo local conditions such as dryness of ground, etc.
An additional benefit arising from the use of such a device
will be a means of obtaining a measure of flow rate under
some conditions by relating the site hydraulics with the
flow depth.
One of the attributes essential to the control system of
an automatic sampler to be used in a storm and/or combined
sewer application is that it be able to withstand power
outages and continue its program. Such power interrup-
tions appear to be increasingly common as demand for
226
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electricity continues to grow- Although desirable in some
instances, the provision of a random interrogate signal to
be coupled with a sequence sample mode generates programming
problems, especially when coupled with power interrupt
possibilities.
Reliability of the control system can dominate the total
system reliability. At the same time, this element will,
in all liklihood, be the most difficult to repair and
calibrate. Furthermore, environmental effects will be the
most pronounced in the control system. The power switching
function of the control system may be required to deal with
multiple switching of inductive loads and must achieve the
switching of these loads without the typical damage asso-
ciated with transfer of energy interruptions.
The above tasks can probably be best executed, in the light
of the current electronics state-of-the-art, by a solid
state controller element. In addition to higher inherent
reliability, such an approach will allow switching of high
level loads in a manner that eliminates RFI emissions and
destructive results. In addition, the unit should be of
modular construction for ease of modification, performance
monitoring, fault location, and replacement/repair. Such
an approach also lends itself to encapsulation which will
minimize environmental effects. Solid state switching
eliminates the possibility of burned or welded contacts
either of which will cause complete sampler breakdown.
Solid state controllers can be easily designed with suffi-
cient flexibility to accept start commands from a variety
of types of remote sensors, telephone circuits, etc.
Low operational current requirements would allow a solid
state controller to continue to operate from a battery
source during a local power outage. This capability
would avoid logic interrupts and attendent loss of data
and allow the sampler operation to be restored immediately
upon the return of power service.
The foregoing discussion as it relates to problems asso-
ciated with interruptions in electrical service is of
course directed to samplers that rely upon outside power
for some aspect of their operation. The need for high sam-
ple intake and transport velocities, larger sample lines
and capacities, together with the possible requirement for
mechanical refrigeration make it unlikely that such a sam-
pler can be totally battery operated today. Although
recent break-throughs have resulted in 1 kw dry cell
227
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batteries, their cost is prohibitive for this sort of an
application. Other approaches to self-contained power such
as custom designed wet cell packs, diesel generators, etc.,
while within the current state-of-the-art, introduce other
problems and complexities that must be carefully weighed
before serious consideration can be given to their incor-
poration in an automatic sampler design.
228
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SECTION X
ACKNOWLEDGEMENTS
The cooperation and support of the commercial manufacturers
and suppliers of automatic liquid sampling equipment and
their representatives is acknowledged with sincere thanks.
They supplied information about their current products and
proposed new developments, took time to answer questions
and provide operational insights, and made the preparation
of much of this report possible. All equipment illustra-
tions were provided by the respective manufacturers, and
appreciation for their use in this report is hereby
acknowledged.
The support of this effort by the Storm and Combined Sewer
Technology Branch of the EPA National Environmental Research
Center, Edison, New Jersey and especially Mr. Richard Field,
Project Officer, and Mr. Harry L. Allen for their guidance,
suggestions and inputs, and thorough manuscript review is
acknowledged with gratitude.
The support and encouragement of the EPA Municipal
Technology Branch, Washington, B.C. and especially
Mr. Sidney Beeman is deeply appreciated.
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SECTION XI
REFERENCES
1. Inter-Agency Committee on Water Resources Report
No. 1, "Field Practice and Equipment Used in Sampling
Suspended Sediment" (1940).
2. American Public Works Association - Research Founda-
tion, "Water Pollution Aspects of Urban Runoff,"
Federal Water Pollution Control Administration, WPCR
Series WP-20-15.
3. Chow, Ven Te, Open-Channel Hydraulics, McGraw-Hill,
New York (1959).
4. "Methods for Chemical Analysis of Water and Wastes -
1971" Environmental Protection Agency Report
No. 16020 07/71.
5. Field, Richard and Struzeski, E.J., Jr., "Management
and Control of Combined Sewer Overflows," Journal
Water Pollution Control Federation, Vol. 44, No. 7
(1972) .
6. American Society of Civil Engineers Task Committee on
Sedimentation Research Needs Related to Water Quality,
"Influences of Sedimentation on Water Quality: An
Inventory of Research Needs," Vol. 97, No. HY8 (1971).
7. Inter-Agency Water Resources Council Report No. T,
"Laboratory Investigation of Pumping Sampler Intakes"
(1966) .
8. "Strainer/Filter Treatment of Combined Sewer Over-
flows;" Fram Corporation; EPA Water Pollution Control
Research Series Report No. WP-20-16:7/69.
9. "Stream Pollution Abatement from Combined Sewer
Overflows;" Burgess and Niple, Ltd.; EPA Water
Pollution Control Research Series Report
No. DAST-32:ll/69.
10. "Control of Pollution by Underwater Storage;" Under-
water Storage, Inc.; EPA Water Pollution Control
Research Series Report No. DAST-29:12/69.
231
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11. "Engineering Investigation of Sewer Overflow Problems;"
Hays, Seay, Mattern, and Mattern; EPA Water Pollution
Control Research Series Report No. 11024 DMA 05/70.
12. "Microstraining and Disinfection of Combined Sewer
Overflows;" Cochrane Division of the Crane Company;
EPA Water Pollution Control Research Series Report
No. 11023 EVO 06/70.
12a. "Microstraining and Disinfection of Combined Sewer
Overflows - Phase II;" Environmental Systems Division
of the Crane Company; EPA Environmental Protection
Technology Series Report No. EPA-R2-73-124,
January, 1973.
13. "Storm Water Pollution from Urban Land Activity;"
AVCO Corporation; EPA Water Pollution Control Research
Series Report No. 11034 FKL 07/70.
14. "Retention Basin Control of Combined Sewer Overflows;"
Springfield Sanitary District; EPA Water Pollution
Control Research Series Report No. 11023 08/70.
15. "Chemical Treatment of Combined Sewer Overflows;"
The Dow Chemical Company; EPA Water Pollution Control
Research Series Report No. 11023 FOB 09/70.
16. "Combined Sewer Temporary Underwater Storage Facility;"
Melpar Company; EPA Water Pollution Control Research
Series Report No. 11022 DPP 10/70.
17. "Urban Runoff Characteristics;" University of
Cincinnati; EPA Water Pollution Control Research
Series Report No. DQU 10/70.
18. "In-Sewer Fixed Screening of Combined Sewer Over-
flows;" Envirogenics Company, A Division of Aerojet
General; EPA Water Pollution Control Research Series
Report No. 11024 FKJ 10/70.
19. "Storm and Combined Sewer Pollution Sources and
Abatement;" Black, Crow, and Eidsness, Inc.; EPA
Water Pollution Control Research Series Report
No. 11024 ELB 01/71.
20. "Storm Water Problems and Control in Sanitary Sewers;"
Metcalf and Eddy, Inc.; EPA Water Pollution Control
Research Series Report No. 11024 EQG 03/71.
232
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21. "Underwater Storage of Combined Sewer Overflows;"
Karl R. Rohrer Associates, Inc.; EPA Water Pollution
Control Research Series Report No. 11022 ECV 09/71.
22. "Maximizing Storage in Combined Sewer Systems;"
Municipality of Metropolitan Seattle; EPA Water
Pollution Control Research Series Report No. 11022
ELK 12/71.
23. Inter-Agency Committee on Water Resources Report No. 5,
"Laboratory Investigation of Suspended Sediment
Samplers" (1941).
24. Inter-Agency Water Resources Council Report No. Q,
"Investigation of a Pumping Sampler With Alternate
Suspended Sediment Handling Systems" (1962).
25. Schulz, E.F., Wilde, R.H. and Albertson, M.L.,
"Influence of Shape on the Fall Velocity of Sedimenta-
tion Particles," Missouri River Division Sedimentation
Series Report No. 5, U.S. Army Corps of Engineers,
Omaha, Nebraska (1954).
26. Inter-Agency Committee on Water Resources Report
No. 12, "Some Fundamentals of Particle Size Analysis"
(1957).
27. Mkhitaryan, A.M., Gidravlika: i OsnoVy Gazodinamiki,
Gosudarstvennoe Izdatel'stvo Tekhnicheskoi
Literatury UkrSSR, Kiev (1959).
28. Knorz, V.S., "Beznapornyi gidrotransport i ego
raschet," Izvestiya Vsesoyuznogo Naucho-
Issledovatel'skogo Instituta Gidravliki, Vol. 44
(1951).
29. Water Pollution Control Federation Manual of Practice
No. 9, Design and Construction of Sanitary and Storm
Sewers (1970).
S GOVERNMENT PRINTING OFFICE : 1973—514-156/367 233
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SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
•?. KtfjJOf . ,(Vu,
iEPA-R2-
w
An Assessment of Automatic Sewer Flow Sampl
ers
5. Report Date
6.
8.,
7. AuthoT(s)
Philip E. Shelley, Ph.D. & George A. Kirkpatrick, P.E.
9. Organization
Hydrospace-Challenger, Inc.
2150 Fields Road
Rockville, Maryland 20850
11, Sponsoring Orgtuihstioa
Repot '-No.
.10. Project No.
11. Contract/Grant No.
68-03-0155
113: '''Type •_•{Repcri and
..-Period Covered
15. Supplementary Notes
«-•-*« j • -f *«--•• ...... , ,
tUS, Environmental Protection Agency
U.S. Environmental Protection Agency report no. EPA-B2-73-261, June 1973.
A brief review of the characteristics of storm and combined sewer flows is
given followed by a general discussion of the purposes for and requirements of a samplin
program. The desirable characteristics of sutomatic sampling equipment are set forth
and problem areas are outlined.
A compendium of over 60 models of commercially available and custom designed
automatic samplers is given with descriptions and characterizations of each unit present
along with an evaluation of its suitability for a storm and/or combined sewer applicatio
A review of field expereince with automatic sampling equipment is given coveri
problems encountered and lessons learned. A technical assessment of...the. state-of-the-
art in automatic sampler technology is presented, and design guides for development of a
new, improved automatic sampler for use in storm and combined sewers are given.
This report was submitted in partial fulfillment of Contract Number 68-03-0155
under the sponsorship of the Office of Research and Monitoring, Environmental Protection
Agency.
17a. Descriptors
Automatic flow samplers, Pollutant variability, Hydraulics, Sampling
program
I7b. Identifiers Storm and combined sewer flows
17c. CO I'/KR Field C: Group
19. Sctmrii:-Ci'-
'.'R'-fo }
:\ ,SY; •-]<•• C
21. ».'(.. ,,f
Send To :
WASHINGTON. D. C. 20240
.,.,.,-.,,....,,,. Shelley & Kirkpatrick
_fm:.->-a Hydrospace-Challenger, Inc.
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