EPA-670/4-75-003
April 1975
APPLICATION AND PROCUREMENT
OF
AUTOMATIC WASTEWATER SAMPLERS
By
Richard P. Lauch
Methods Development and Quality Assurance Research Laboratory
Program Element No. 1HA327
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
-------
REVIEW NOTICE
The National Environmental Research Center -- Cincinnati
has reviewed this report and approved its publication.
Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
11
-------
FOREWORD
Man and his environment must be protected from the adverse effects
of pesticides, radiation, noise and other forms of pollution, and
the unwise management of solid waste. Efforts to protect the
environment require a focus that recognizes the interplay between
the components of our physical environment--air, water, and land.
The National Environmental Research Centers provide this multi-
disciplinary focus through programs engaged in
• studies on the effects of environmental
contaminants on man and the biosphere, and
• a search for ways to prevent contamination
and to recycle valuable resources.
This report is part of a continued effort by the Instrumentation
Development Branch, Methods Development and Quality Assurance
Research Laboratory (MDQARL), NERC-Cincinnati, to investigate
instruments and provide information to both users and suppliers.
The intention is also to upgrade instrumentation, and to make it
possible to choose the most suitable instrument for a particular
application.
A. W. Breidenbach, Ph.D.
Director
National Environmental
Research Center, Cincinnati
111
-------
ABSTRACT
Application and procurement of automatic sampling devices are
discussed. Different sampler characteristics including com-
positing, proportionality, preservation, lift, and power are
described. Manufacturers are listed. Application is discussed
with reference to compliance with the National Pollutant Discharge
Elimination System permit program, treatment plant control, and
other uses. Method of selection and procurement (involving
application, familiarization, and purchase) are discussed.
IV
-------
CONTENTS
Page
Abstract iv
Acknowledgement vi
Sections
I Conclusions 1
II Recommendations 2
III Introduction 3
IV Methods of Sampling
Basic Sampler Types 4
Proportionality 5
Preservation 6
Type of Lift 7
Power Requirements 8
Manufacturer 9
Special Samplers 11
V Sampler Application
Permit Program Compliance 12
Treatment Plant Control 13
Special Applications 13
VI Procurement of Automatic Water Samplers
Method of Procurement 15
Sampler Selection 18
VII Discussion 19
•VIII References 21
-------
ACKNOWLEDGEMENT
The author gratefully acknowledges the assistance of R. H.
Pohlkamp for his help in preparing the section on procurement
of automatic water samplers.
VI
-------
SECTION I
CONCLUSIONS
The National Pollutant Discharge Elimination System (NPDES) permit
program has intensified the importance of automatic wastewater
samplers. Automatic samplers have been used for years to collect
routine samples from sewers, effluents, and streams, and now these
samplers will be required to provide even more accurate informa-
tion; information that is proportioned to time or flow and used
for the specific purpose of determining permit compliance or non-
compliance.
Many different types of automatic samplers are commercially
available, and they employ different methods of compositing, pro-
portioning, preserving, and lifting the sample. Most all sampling
requirements can be fulfilled with commercially available units,
although most of these units still require improvement in accuracy,
dependability, method of preservation, proportioning, and overall
design.
Along with automatic sampling for permit compliance, the automatic
sampler has application involving treatment plant control, mate-
rials balance, specific process waste, storm and combined sewers,
instrumentation evaluation, and sewer district surcharges.
Sampler purchase should be preceded by a conscientious review of
the application and an awareness of many different types of auto-
matic units available and the situations in which they are used.
Questions that arise when purchasing sampling equipment should be
resolved by contacting procurement officers or purchasing agents.
-------
SECTION II
RECOMMENDATIONS
Before automatic samplers are used, they should be thoroughly
evaluated to determine their performance, including accuracy and
precision of timer or flow proportioning, adequacy of preservation,
spurious cycles, battery endurance, and other criteria.
The proper method of collecting a representative sample, including
intake design, positioning of the intake within the channel, and
correct inlet velocity for representative suspended solids, must
be researched.
Rather than designing your own unit, commercially available sam-
plers should be purchased if they will fulfill one's needs.
Presently, many companies manufacture this equipment; the strong
competition encourages continuous incorporation of new ideas and,
therefore, samplers for most application are commercially avail-
able. For special applications an established manufacturer can
put the ideas of both the user and vendor into practice.
A thorough knowledge of the application of and familiarity with
samplers should be obtained before purchase. Procurement offices
can provide information on and answer questions about purchasing
these samplers.
-------
SECTION III
INTRODUCTION
The Federal Water Pollution Control Act Amendments of 1972 (PL
92-500) sets a national goal to eliminate pollutants discharged
into navigable waters by 1985. This law requires industries to
use the "best practicable" technology to control water pollution
by July 1, 1977, and the "best available" technology by July 1,
1983. Publicly owned waste treatment plants are required to pro-
vide a. minimum of "secondary treatment" by July 1, 1977, and to
apply the "best practicable" technology by July 1, 1983.
The U.S. Environmental Protection Agency (EPA) is required to
establish national effluent limitations and national performance
standards for sources of water pollution. Effluent limits may
allow some or no discharge at all depending on the specific pol-
lutant to be controlled.
The NPDES^ permit is the mechanism for ensuring that effluent
limits are met. This permit regulates what and how much may be
discharged; the permittee is committed to reduce or eliminate his
discharge in an orderly fashion, in specified steps, at specified
times. The permit contains a compliance schedule; without waiting
for final compliance, each step is legally enforceable and clear
limits are put on discharges while the polluter is moving toward
compliance.
A waste monitoring program is necessary to assure the regulatory
agencies that the effluent requirements are met and that the im-
plementation schedule set forth in the permit is being maintained.
Monitoring is also required to control in-plant operations so that
violations of permit specifications can be prevented. Under the
permit system, the burden of monitoring a waste stream is placed
upon the party creating the discharge. Regulatory agencies will
monitor only as a check upon the accuracy of the results of the
discharger. The discharger must collect effluent samples for
analyses of the specific parameters listed in the permit. Reports
including these data are required periodically by the Federal or
state agency that issued the permit. Hence, the need for auto-
matic sampling devices is readily apparent. Automatic equipment,
when properly installed, will accurately and precisely take waste
samples in proportion to time or flow, preserve the sample, and
save the use of manpower.
-------
SECTION IV
METHODS OF SAMPLING
BASIC SAMPLER TYPES
Samples may be taken in the following ways:
1. Grab
2. Simple composite
a. continued
b. sequenced
3. Discrete composite
a. single aliquot per sample
b. multiple aliquot per sample
c. multiple samples per aliquot
4. Continuous monitoring
These basic methods of sampling can all be proportioned to either
time or flow. The basic method is discussed here, and proportion-
ality is discussed later.
A single grab sample is sufficient to characterize waste for a
period of time through which the concentration and flow rate were
essentially constant. A new grab sample is required if the con-
centration or flow rate changes. Possibly, the concentration will
change and not flow, but this is unlikely.
A simple composite sample is collected into a single container
over a known period of time. The sample can be composited con-
tinuously with a low-flow-rate pump or a dipper mechanism, or it
can consist of aliquots periodically pumped into the container.
The discrete composite sampler contains a number of bottles that
are filled sequentially. These samplers can be programmed to take
single aliquots per bottle, multiple aliquots per bottle, or mul-
tiple bottles per aliquot. Depending on the manufacturer, one,
two, or all three of these methods of filling are included on the
same sampler. The ability to deliver the same aliquot to more
than one bottle is necessary if different preservatives are re-
quired. Discrete bottle samplers are used to detect changes in
waste concentrations at specific times during the sampling period,
and portions of the discrete samples can still be composited into
a single sample if desired.
-------
Continuous monitors may be needed to obtain information that is
required on specific parameters for treatment plant control.
Toxic substances from an industrial effluent may also require
continuous monitoring so they can be diverted before entering a
treatment plant, where they could upset the process, or before
entering a receiving stream, where they could cause a fish kill
or impair human health. Continuous monitors are beyond the scope
of this report, but one should be aware of their availability for
situations were instant, on-line data are required. Mentink4>->,6
gives details on continuous monitors and functional components
such as telemetering and computerization.
PROPORTIONALITY
The above sampler types can collect samples proportional to time
or flow. Time proportionality consists of an accurate and precise
timer that initiates a sampling cycle at preset intervals. Timers
can be powered by electricity, pressure, or a spring. Electrically-
powered timers are probably the most accurate. Another method of
time proportioning a sample is to use a constant speed, low-flow-
rate metering pump.
Collecting the sample proportional to flow is more difficult. One
time-consuming method is taking grab samples at definite intervals
and using the record of plant flow to make a flow-proportioned
composite. Samples from an automatic discrete sampler can also be
manually composited proportional to flow. In all modern waste
treatment plants, flow should be measured and recorded; a signal
from this existing flow-measuring equipment can be used to make
the simple composite and discrete samplers automatically propor-
tional to flow. Some sampler manufacturers also supply their own
flow-proportioning equipment. This equipment consists of a device
for measuring water level (usually a float, bubbler, dipper, or
electrode) above the crest of a weir or flume. This head signal
is processed electrically or electromechanically to supply a flow-
proportional contact closure. Some flow-proportional samplers are
also programmed to apply Manning's equation for open channel flow;
here the characteristic channel dimensions, slope, and roughness
must be known, but a weir or flume is not required.
Flow-proportioned samples can be taken in one of these four ways:
1. TCSVV (continuous sample, volume varying) - sampling pump
flow rate proportional to stream flow.
-------
2. TV (time constant, volume varying) - sample volume
proportional to instantaneous flow rate.
3. TCV~V (time constant, volume varying) - sample volume
proportional to flow since last sample.
4. TyVc (time varied, volume constant) - time between samples
is proportional to flow.
The sample obtained with Method (1) gives a sample that is most
representative of the stream. In most instances, however, this
method is not practical because the sample flow rate should always
be high enough to give accurate suspended solids results and such
a flow rate would require an excessively large sample volume.
Accurate electronic control of this system is also complicated and
expensive. Methods (2), (3), and (4) are most commonly used, and
all three have an inherent error, which has been illustrated by
Shelley' in specific examples. The error, however, is not as
great as that obtained by a simple composite sample that is pro-
portional to time.
PRESERVATION
o
Methods for sample preservation, such as cooling or chemical
addition, or both, should be incorporated when automatic samplers
are used. Some samplers include refrigeration and others have
sample compartments that can be iced. It was mentioned earlier in
this report that some discrete samplers fill more than one bottle
with the same aliquot, allowing the addition of different chemical
preservatives to these bottles. Biochemical oxygen demand (BOD),
an important parameter for biological treatment plants, changes
rapidly after the sample is taken. The maximum holding period for
BOD samples is 6 hours at 4C^; this indicates that four consecutive
BOD samples made up of 6-hour flow-proportioned composites, which
were iced at approximately 4C, could be used to estimate plant
effluent over a 24-hour period. The acceptance of chemical oxygen
demand (COD) or total organic carbon (TOG) results in lieu of BOD
was proclaimed in the Federal Register for situations where long-
term BOD:COD or BOD:TOC correlation have been demonstrated. COD
and TOC can be preserved for longer periods than BOD when the
appropriate preservatives are used and, therefore, are more con-
ducive to automatic sample takers.
The sanitary engineer should always discuss his sampling program
with the chemistry laboratory personnel responsible for sample
analysis before the study begins. This will result in data that
-------
are more accurate and in fewer scrapped samples. For example,
hydrolyzable phosphorus is preserved by cooling and ^804. Ortho-
phosphate requires only cooling; the addition of t^SC^ would scrap
this sample. The chemistry staff also has an idea of the buffer-
ing capacity of the waste and can tell the engineer the quantity
of HoSO* required to preserve certain samples. Good relations and
teamwork are required between all disciplines (biology, chemistry,
and engineering) to get the best results.
TYPE OF LIFT
The following methods are used to force a water sample from the
source to the sampler: gas pressure, gravity, pump, scoop, and
flow proportional scoop (Trebler).
The basic gas-pressure type of sampler consists of a small cham-
ber and check valve, which are located within the waste stream.
Two lines connect this chamber to the main sampler where the
sample container, a. small cylinder of freon or nitrogen, and the
controls (including a pressure regulator, timer, and valves) are
housed. The entire unit, including the timer, is powered from
the gas cylinder. Gravitational forces unseat the check valve
when the chamber is vented, and a water sample enters. Valves,
activated by the timer, allow gas pressure to enter through one
line and force the water sample up the other line into the sample
container. With this type of sampler, the chamber fills immedi-
ately after the sample was taken and the sample is not forced
into the sample container until the timer initiates a new cycle.
Samplers of this type are useful when a simple composite sample
is required from a field location with no electric power.
One type of gravity system consists of a container with two
openings placed under the surface of the waste stream. One
opening is the sample inlet, and the other is attached to a line
and needle valve. The sample enters the container at a rate
proportional to the air leaving through the needle valve. Various
types of siphoning mechanisms are also classified as gravity sys-
tems. Gravity systems clog readily because of lack of power, and
the samples are not accurately proportioned to time or flow. More
representative samples can be obtained from samplers that are
powered from sources other than gravity and that have been pur-
chased from reputable manufacturers.
Most samplers use a pump to force the water from the waste stream
-------
to the sampler. Pumps are either mounted within the waste stream
(submersible) or within the sampler. Submersible pumps obstruct
the flow, catch debris, and may become clogged; however, they have
the advantage of supplying sample under positive pressure, can
overcome greater lifts, and cannot lose prime or suck in nonrepre-
sentative material from the atmosphere. Pumps located within the
sampler, operate under negative lift and cannot draw water through
a vertical distance of more than one atmosphere (about 34 feet at
sea level). From a practical standpoint, it is best to locate the
pump as close to the water as possible, and a good rule of thumb
is not to exceed half an atmosphere of vertical lift (about 17
feet). Sampler-mounted pumps are handy, and they usually present
no problems. It is easier to mount an intake within a waste
stream than a pump, which is large and also contains electrical
leads. Sampler-mounted pumps are usually positive displacement
and of one of the following types: peristaltic, piston, impeller,
or diaphragm.
The peristaltic pump can be either rotary or reciprocating; it
merely squeezes the flexible tubing and the sample does not come
in contact with pump components, which could cause contamination.
Piston pumps are usually of the small, syringe type that supply
sample continuously at a low rate. Flexible, neoprene, impeller
pumps usually supply a continuous flow at a high rate; periodi-
cally a timer-activated valve opens and a portion of the sample
enters a container. Diaphragm pumps (paced by a timer or flow-
meter) periodically create a vacuum on the sample container;
water is sucked into the container but does not pass through the
pump.
The lifting mechanism can also consist of a number of scoops or
buckets mounted on a belt or chain. Periodically these buckets
automatically dip samples from the waste stream.
The Trebler sampler is a scoop with characteristic dimensions such
that it delivers a sample proportional to flow when mounted up-
stream from a weir or flume.
Illustrations of different lifting mechanisms are given in the
Handbook for Monitoring Industrial Wastewater.
POWER REQUIREMENTS
Samplers are powered by gravity, pressure, or electricity (115
-------
VAC or battery). Pressure and electrically operated units are
more accurate and reliable than are gravity flow samplers. My
experience has been that electrically powered timers are more
accurate than those that are powered by gas pressure. Pressure
or battery powered units are almost a necessity for remote field
locations. Many electrical units operate from 12 VDC, which can
be supplied from a 115 VAC/12 VDC converter or a 12 volt battery.
The converter is also used to charge the battery. Some sampler
manufacturers supply 12 volt nickel-cadmium rechargeable batteries
that are light in weight and dependable. When battery powered
samplers are used, an extra converter and battery should be pur-
chased so that one fully charged battery is always ready for field
use.
MANUFACTURER
There are many sampler manufacturers. Shelley' describes most of
the samplers made in the United States, and Wood^ reported on the
results of a survey on English samplers. At present, the art of
sampling is changing so fast that no attempt is made here to
describe all the samplers. Current information can be requested
from the list of manufacturers that follows. (And I apologize to
any company that was inadvertently omitted.)
BIF Sanitrol
P.O. Box 4
Largo, Florida 33540
(813) 584-2157
Brailsford and Company, Inc.
Milton Road
Rye, New York 10580
(914) 967-1820
Brandywine Valley Sales Company
P.O. Box 243
Honey Brook, Pennsylvania 19344
(215) 273-2841
Bristol Engineering Company
204 S. Bridge Street
Box 696
Yorkville, Illinois 60560
(312) 553-7161
Chandler Development Company
1031 E. Duane Avenue
Sunnyville, California 94086
(408) 738-1060
Environmental Equipment Divi-
sion, FMC Corporation
1800 FMC Drive
Itasca, Illinois 60143
(312) 893-1800
ETS Products
12161 Lackland Road
St. Louis, Missouri 63141
(314) 878-1703
Fluid Kinetics Inc.
3120 Production Drive
Fairfield, Ohio 45014
(513) 874-5120
-------
Horizon Ecology Company
7435 North Oak Park Avenue
Chicago, Illinois 60648
(312) 647-7644
Hydragard Automatic Samplers
850 Kees Street
Lebanon, Oregon 97355
(503) 258-2628
Hydra-Numatic Sales Company
65 Hudson Street
Hackensack, New Jersey 07602
(201) 489-4191
Instrumentation Specialties
Company, Inc.
P.O. Box 5347
Lincoln, Nebraska 68524
(402) 799-2441
Lakeside Equipment Corporation
1022 E. Devon Avenue
Bartlett, Illinois 60103
(312) 837-5640
Manning Environmental Corpora-
tion
120 DuBois Street
Box 1356
Santa Cruz, California 95061
(408) 427-0230
Markland Specialty Engineering,
Ltd.
Box 145
Etobicoke, Ontario, Canada
(416) 625-0930
N-Con Systems Company, Inc.
Clean Waters Building
New Rochelle, New York 10801
(914) 235-1020
NP Enterprises Inc.
P.O. Box 69
Lewiston, New York 14092
(716) 754-4828
Phipps and Bird, Inc.
Sixth and Byrd Streets
P.O. Box 2-V
Richmond, Virginia 23205
(804) 644-5401
ProTech Inc.
Roberts Lane
Malvern, Pennsylvania 19355
(215) 644-3854
Quality Control Equipment Com-
pany
P.O. Box 2706
Des Moines, Iowa 50315
(515) 285-3091
Sigmamotor, Inc.
14 Elizabeth Street
Middleport, New York 14105
(716) 735-3616
SIRCO Controls Company
8815 Selkirk Street
Vancouver
British Columbia, Canada
261-9321
Sonford Products Corporation
100 E. Broadway, Box B
St. Paul Park, Minnesota 55071
(612) 459-6065
Testing Machines, Inc.
400 Bayview Avenue
Amityville, New York 11701
(516) 842-5400
10
-------
TRI-AID Sciences Inc.
161 Norris Drive
Rochester, New York 14610
(716) 461-1660
SPECIAL SAMPLERS
Many samplers have been designed for special purposes, and the
results of using some of these devices have been reported.7»H-18
Earlier, I suggested that purchasing a commercially available
sampler is economically more feasible than developing an in-house
design. Special application, however, may require custom equip-
ment. First, find out what is available, read reports, request
brochures. Then, contact an established manufacturer to build
the individually designed equipment. The result will be a better
sampler.
11
-------
SECTION V
SAMPLER APPLICATION
PERMIT PROGRAM COMPLIANCE
Under the NPDES permit program, dischargers are required to monitor
and report the amount and nature of all waste components. There-
fore, factories, power plants, sewage treatment plants, and animal
feedlots must sample their waste for permit compliance. The type
of sample required to fulfill permit obligations can be determined
from the permit. A grab sample might be satisfactory; a 24-hour
composite could be required; and in some cases such as for toxic
substances continuous monitoring might be necessary. An example
of effluent limitations from an industrial waste is given in the
following table which was taken from reference 2.
FINAL EFFLUENT LIMITATIONS
Effluent
Characteristic
Flow
Total Susp. Solids
Chromium, Total
Copper, Total
Iron, Total
Nickel, Total
Oil & Crease
Chloride
Sulfate
Sulfide
Discharge Limitation'"
.. kg/day (Ibs/day)
Daily Daliy
Average Maximum
4.4 (9.5)
.06 (.14)
.06 (.12)
.27 (.6)
.11 (.24)
3.2 (7.1)
6.5 (14.3)
.09 (.21)
.09 (.18)
.41 (.9)
.17 (.36)
4.8 (10.7)
Other Limitations
< Specify Units)
Average Maximum
Monitoring Requirements
Frequency Sample
Measurement Type
DAILY ESTIMATE
Weekly 24-hr. Composite
Weekly 24-hr. Composite
Weekly 24-hr. Composite
Monthly 24-hr. Composite
Weekly 24-hr. Composite
Weekly 6 Grabs/24 hrs.
Monthly 24-hr. Composite
Monthly 24-hr. Composite
Monthly 24-hr. Composite
' Net additions to intake
The monitoring requirements given in the table are six grab
samples per 24 hours for oil and grease and monthly and weekly
24-hour composite samples for the other effluent characteristics.
Discharge limits are given in pounds per day, and therefore, the
samples must be proportioned to flow. Existing methods of com-
positing a flow-proportional sample have an inherent error;7
however, present samplers that perform within specifications may
be used. The reading in parts per million from these composites
times the daily flow times the corresponding specific weight
divided by 106 will give sufficiently accurate results at this
time. The parameters listed in the table require four different
preservatives": nitric acid for chromium, copper, iron, and nickel;
sulfuric acid plus cooling for oil and grease; cooling for sulfate;
12
-------
and zinc acetate for sulfide. Therefore, four different composite
samples are required to allow for the four different preservatives.
Because the EPA and the state water pollution control agencies can
also sample a permittee's effluent, they also require automatic
wastewater samplers. PL 92-500 requires all U.S. Government agen-
cies to comply with Federal, state, interstate, and local water
pollution control laws and regulations, just as any nongovernment
source must comply. Therefore, automatic samplers are used by
Federal agencies in monitoring their own effluent.
There are also instances where an industry passes on its effluent
to the local municipal plant for treatment. Automatic samplers
along with flow records are required here to determine the sur-
charge due to the local sewer district. If the effluent is toxic,
continuous monitoring may be required. The effluent might have
to be diverted to keep a local plant using a biological treatment
process from being upset.
TREATMENT PLANT CONTROL
Automatic wastewater samplers are useful for treatment plant con-
trol and for determining plant efficiency. Discharge permits may
also require data showing overall treatment plant efficiency.
Samplers are also useful to determine efficiencies across specific
parts of the treatment plant, such as the primary clarifier and
the activated sludge process, or across specific chemical treatment
processes. Samplers can be used initially to point out locations
within the treatment plant where continuous monitoring for control
or identification of toxic materials is required.
SPECIAL APPLICATIONS
A very beneficial use of automatic wastewater samplers is collec-
ting waste samples after specific processes within an industrial
plant to point out a process wherein raw materials are being
wasted. The use of wastewater samplers to run a materials
balance for an entire plant many times will result in both re-
ducing pollution and saving raw materials and their costs. In
many cases, the use of raw materials may be reduced at specific
processes or they may be salvaged from the final effluent for
recycling.
Automatic samplers also aid in evaluating continuous monitors
(single or multiparameter). O'Herron-^ evaluated a cyanide
13
-------
monitor in which an ISCO sampler was used to collect some of
the comparison samples.
Automatic water samplers can be used in combined storm/sanitary
sewers and within waste bypass sewers. In these situations, the
sampler can be programmed to turn on during the storm or overload
period.
14
-------
SECTION VI
PROCUREMENT OF AUTOMATIC WATER SAMPLERS
Understanding the intricacies of the procurement process is helpful
because, if satisfactory samplers specific for application are to
be obtained, the user must become involved along with the Pro-
curement Officer. In the paragraphs that follow, R. H. Pohlkamp
(Director, Contracts Management Division, NERC-Cincinnati, USEPA,
Cincinnati, Ohio) discusses several regulations and considerations
governing procurement procedures and practices applicable to the
USEPA.
METHODS OF PROCUREMENT
Only contracting officers are delegated authority to enter into
contracts for equipment, supplies, and services on behalf of the
Government. Before any contract is entered into, modified, or
terminated, all required reviews, clearances, or approvals must be
obtained, and all requirements of the applicable Federal Procure-
ment Regulations must be met.
The Federal Procurement Regulations require that all purchases and
contracts shall be made by Formally Advertising Invitation for
Bids (IFB) that contain adequate specifications and conditions and
that allow sufficient bidding time before being opened to permit
full and free competition consistent with the needs of the Govern-
ment and the type of item being procured.
Exceptions to the IFB requirement exist but only under well-defined
circumstances where the use of IFB is not feasible and not practi-
cable.
Four examples of exceptions that may apply to the purchase of Auto-
matic Water Samplers are:
1. The aggregate amount of the purchase does not
exceed $2500.00.
2. The equipment can be obtained from only one
manufacturer (sole source of supply).
3. Competition is precluded because of the existence
of patent rights, secret processes, or control of
basic raw material.
4. When it is impossible to draft, for an IFB,
adequate specifications or any other adequately
15
-------
detailed description of the required equipment.
Such exceptions become the authority to procure by negotiation and
utilize the Request for Proposal (RFP) mechanism. Following are
excerpts from the "EPA Guide for Contract Project Officers" in-
serted here for the purpose of distinguishing between the IFB and
the RFP mechanism.
"Many people consider the word 'advertised1 to be
synonymous with 'competition' and the word 'negotia-
tion' to be synonymous with 'sole source'. This is
not the case and often causes much confusion for the
Project Officer and eventually the Contracting
Officer. The basic criteria for an advertised (IFB)
contract situation are as follows:
1) It is possible to define adequately the contract
requirements to the extent that qualified bid-
ders can provide fixed price bids on an equal
technical basis for like equipment.
2) The Contracting Officer is willing to make a
contract award to the lowest responsive bidder
without a need for a technical evaluation and
without discussion with the bidders.
3) It is reasonable to believe that more than one
source can provide a bid on the equipment
requirement.
"In contrast, the basic criteria for negotiated
situation are as follows:
1) It is not possible to adequately define con-
tract specifications to the extent that the
Government would be satisfied by awarding the
contract to the lowest offerer based on price
competition alone.
2) The Contracting Officer determines that another
form of evaluation is required.
3) If after a market survey of existing scientific
equipment, it is determined by the Contracting
Officer that there is only one source who can
meet the requirements of the proposed contract.
"According to existing laws, regulations, and good
16
-------
business practice the Contracting Officer must first
consider the element of competition in a negotiated
contracts situation. If the RFP method is deter-
mined to be more appropriate than the IFB method,
this is not justification in itself for sole source
contracting. In both IFB and RFP situations, com-
petition is the first consideration."
All requests for purchase shall be initiated on EPA Form 1900-8
Procurement Request/Requisition, and be accompanied by specifi-
cations that adequately and accurately describe the requirement.
To the extent possible, specifications for use in formal adver-
tising should be performance specifications setting forth the
minimum requirement of the Government. The specification must be
complete and specific but designed to enable the widest competi-
tion by qualified bidders.
(Author's note: EPA has continually employed the philosophy of
widest competition in water quality monitor procurement with its
own specifications^ and has provided similar opinions to other
agencies such as California State Water Pollution Control
and discussions provided to the NERC-Cincinnati Training Center
have also given consideration to specification formulation. 2
Including details peculiar to one brand or make of equipment and
not critical to the need to be met results in unnecessary re-
strictions of competition and is to be avoided.)
Where it is impossible, impracticable, or uneconomical to prepare
performance specifications or where design specifications, if
prepared, would unduly restrict competition, a "Brand Name or
Equal" purchase description may be used. Under this technique,
one or more brand name(s) (and model number) of acceptable equip-
ment together with a listing of its salient characteristics is
used in lieu of a specification. The requirements are advertised
and IFB's sent to all interested bidders. Bids offering the
referenced brand name or other equipment purporting to be equal
to the brand name and having the salient characteristics listed
in the IFB will be considered for award. A technical evaluation
of all equipment offered will be performed by the requisitioner
or other technical personnel based on the manufacture's descrip-
tive literature submitted with his bid. Award will be made to
the lowest bidder offering a product that is determined to be
equal in all material respects of the brand name product and
in the salient characteristics referenced in the IFB.
17
-------
SAMPLER SELECTION
Three steps should be followed in purchasing automatic sampling
equipment:
1. know the application
2. become familiar with automatic wastewater samplers
3. pick sampler and purchase equipment.
Initially, the user must know the exact application for the samp-
ling equipment that he is going to purchase. It was mentioned
earlier in this report that automatic samplers may be required for
permit compliance, treatment plant control, and various other
applications. When picking a sampler for a specific application
the following must be considered: power requirements, flow or
time proportioning, single composite or multiple discrete sam-
ples, multiplexing, lift, preservatives, cooling, portable or
stationary, weight and dimensions, and will the unit collect a
representative suspended solids sample for the specific applica-
tion.
If the user is not already familiar with automatic wastewater
samplers, he should become familiar with them. He may do this by
contacting agencies that are presently using samplers; they are
usually more than willing to show off their equipment. Some of
these agencies are:
1. EPA Regional Surveillance and Analysis Divisions
located in each of the 10 regions.
2. State and local environmental protection agencies.
3. EPA, National Field Investigation Centers in Denver,
Colorado, and Cincinnati, Ohio.
4. EPA, Methods Development and Quality Assurance
Research Laboratory in Cincinnati, Ohio.
Finally, pick a sampler to satisfy your needs. Contact manu-
facturers and study the brochures describing their samplers,
including the prices. Shelley's report' is a handy guide to sam-
pler selection, the U.S. Army^ has initiated an evaluation of
water samplers, and EPA ' ' can supply sampler information.
After obtaining this information and reviewing it conscientiously,
one can rationally select the proper sampler. If questions or
problems arise in purchasing the needed equipment, consult your
Procurement Officer.
18
-------
SECTION VII
DISCUSSION
The NPDES permit, which evolved from (PL 92-500) is the mechanism
for ensuring that effluent limits are met; it requires dischargers
to analyze effluent samples for specific parameters listed in the
permit. These data will be used to determine permit compliance
and this raises the level of importance of the automatic waste-
water sampler and illustrates the necessity for sampling equipment
that is both accurate and precise. Data obtained must be repre-
sentative of the effluent, and their accuracy can be no better
than that of the equipment used to collect the sample.
Many different manufacturers produce various types of wastewater
samplers. When a sampler is purchased to collect samples for
permit compliance, the type of sampler selected should be based on
the data requirements of the permit. If the effluent limitation is
listed in pounds/day, then the sample must be proportioned to flow
and the equipment must be able to collect samples that are propor-
tional to flow. Most methods of collecting a flow-proportional
sample have inherent error because they sample periodically and
only the time between samples is flow proportional or the size of
the aliquot is flow proportional. A continuous sampling pump with
a flow rate that varies in proportion to wastewater flow rate
would give a sample that is truly proportional, but this type of
sampler presents functional and design difficulties.
Continuous monitors should be installed where instant data are
required, such as detecting toxic substances or detecting parame-
ter limits that mandate immediate changes in plant control.
Preservation requiring cooling and chemical addition is necessary
for many parameters and this must be considered when purchasing a
sampler.
Power requirements, whether they be gravity, pressure, battery,
or utility company, must be considered before purchase.
Collecting a representative sample involves intake design, place-
ment within the channel, and velocity; these items need to be
considered before purchasing. Additional research is also re-
quired to determine the best method for collecting a sample that
is representative of the waste stream for all parameters including
19
-------
suspended solids.
Although purchasing a sampler may require written specifications,
the mechanics of the purchase should not become involved if one is
aware of procurement methods and consults his procurement officer
when advice is required.
20
-------
SECTION VIII
REFERENCES
1. Public Law 92-500, "Federal Water Pollution Control Act
Amendment of 1972," 70 Stat. 498, 84 Stat. 91.33 USC 1151,
October 18, 1972.
2. U.S. Environmental Protection Agency, "Toward Cleaner Water -
The New Permit Program to Control Water Pollution," U.S.
Government Printing Office, Washington, D.C. 20402, 546-312/
140, 1973.
3. U.S. Environmental Protection Agency, "Guide for Wastewater
Monitoring," 1972.
4. Mentink, A. F., "Specifications for an Integrated Water Quality
Data Acquisition System," 8th Edition, FWPCA, Cincinnati,
Ohio, January 1968.
5. Mentink, A. F., "Specifications for Telemetering Systems for
Water Quality Surveillance," U.S. Public Health Service,
Cincinnati, Ohio, May 1965.
6. Mentink, A. F., "Specifications for a Digital Data Logger for
Water Quality Monitoring Instrumentation Systems," FWPCA,
Cincinnati, Ohio, May 1968.
7. Shelley, P. E., and Kirkpatrick, G. A., "An Assessment of
Automatic Sewer Flow Samplers," prepared for Office of
Research and Monitoring, U.S. Environmental Protection Agency.
U.S. Government Printing Office, Washington, D.C. 20402, EPA-
R2-73-261, June 1973.
8. Methods Development and Quality Assurance Research Laboratory,
National Environmental Research Center, Cincinnati, Ohio,
"Methods for Chemical Analysis of Water and Wastes," U.S. EPA,
Technology Transfer, Washington, D.C.., 1974.
9. Federal Register, Monday, April 30, 1973.
10. U.S. Environmental Protection Agency, "Handbook for Monitoring
Industrial Wastewater," Technology Transfer, August 1973.
21
-------
11. Wood, L. B., and Stanbridge, H. H., "Automatic Samplers,"
Journal Water Pollution Control Federation, 495-520, 1968.
12. Sugar, J. W., and Brubaker, J. H., "Sampling for Wastewater
Analyzers, Part I: Systematic Approach," Union Carbide Corp.,
Instrumentation Technology, Vol. 20, No. 6, 27-32, June 1973.
13. Sugar, J. W., and Brubaker, J. H., "Sampling for Wastewater
Analyzers, Part II: Effective Applications," Union Carbide
Corp., Instrumentation Technology, Vol. 20, No. 8, 39-42,
August 1973.
14. Carr, R. R., "Combined Sampling and Flow Measurement," Public
Works, Vol. 104, No. 4, April 1973.
15. Robbins, J. W. D., and Kriz, G. J., "For Pollution Studies:
An Automatic Liquid Sampler," Agricultural Engineering,
December 1970.
16. Stephenson, R. L. , and Oatiss, W. E., "Installation of Sampling
Equipment in Manholes," Deeds and Data, Water Pollution Control
Federation, Washington, D.C., 20016.
17. Jebens, H. J., and Thomas, R. H., "A Flow Proportional Com-
posite Sampler," Water and Sewage Works, September 1970.
18. Doty, R. D., "A Portable Automatic Water Sampler," Water
Resources Research, Vol. 6, No. 6, December 1970.
19. O'Herron, R. J., "The Performance Evaluation of the Orion
Cyanide Monitor," unpublished report, U.S. Environmental
Protection Agency, National Environmental Research Center,
Cincinnati, Ohio, June 1974.
20. Lauch, R. P., "Performance of the ISCO Model 1391 Water and
Wastewater Sampler," unpublished report, U.S. Environmental
Protection Agency, National Environmental Research Center,
Cincinnati, Ohio, 45268, April 1974.'
21. Mentink, A. F., "An Opinion on Water Quality Instrumentation
for the San Joaquin and Sacremento Delta Project for the State
of California," unpublished report, U.S. Environmental
Protection Agency, National Environmental Research Center,
Analytical Quality Control Laboratory, Cincinnati, Ohio,
November 1972.
22
-------
22. Mentink, A. F., "Development of Specifications for Automatic
Water Pollution Surveillance Instruments," unpublished report
presented to EPA personnel at the National Environmental
Research Center, U.S. Environmental Protection Agency, Cincin-
nati, Ohio.
23. Barkley, J. J., Peil, K. M., and Sorber, C. A., "Water Pollu-
tion Sampler Evaluation," U.S.A. Medical Biological Research
and Development Lab., EQD, Fort Deitrich, Frederick, Md.,
21701, In-house report, February 1975.
24. Harris, D. J., and Keffer, W. J., "Wastewater Sampling Method-
ologies and Flow Measurement Techniques," U.S. Environmental
Protection Agency, Region VII, Surveillance and Analysis
Division, Technical Support Branch, Field Investigations
Section, June 1974.
25. Walter, C. M. , unpublished Summary of Questionnaires from
Regions, U.S. Environmental Protection Agency, Surveillance
and Analysis Division, Region VII, 25 Funston Road, Kansas
City, Kansas.
23
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-670/4-75-003
2.
4, TITLE AND SUBTITLE
Application and Procurement of Automatic W
Samplers
7. AUTHOR(S)
Richard P. Lauch
3. RECIPIENT'S ACCESSION-NO.
5. REPORT DATE
April 1975; Issuing Date
ast^wfite7*
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO,
9. PERFORMING ORGANIZATION NAME AND ADDRESS
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
12. SPONSORING AGENCY NAME AND ADDRESS
Same as above
10. PROGRAM ELEMENT NO.
1HA327; ROAP 24ALE; TASK 04
11. CONTRACT/GRANT NO.
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Application and procurement of automatic sampling devices are discussed. Different
sampler characteristics including compositing, proportionality, preservation, lift,
and power are described. Manufacturers are listed. Application is discussed with
reference to compliance with the National Pollutant Discharge Elimination System
permit program, treatment plant control, and other uses. Method of selection and
procurement (involving application, familiarization, and purchase) are discussed.
17.
KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
Samplers, Sampling, Acceptance sampling,
Continuous sampling, Sequential sampling,
Water pollution
13. DISTRIBUTION STATEMENT
Release to public
b.lDENTlFIERS/OPEN ENDED TERMS
Water sampler applica-
tion, Water sampler
procurement, Wastewater
samplers, Effluent sam-
pler application,
Automatic wastewater
samplers
19. SECURITY CLASS (This Report)
Unclassified
20 SECURITY CLASS (This page)
Unclassified
c. COS AT I Field/Group
13B
21. NO. OF PAGES
30
22. PRICE
EPA Form 2220-1 (9-73)
24
U. S. GOVERNMENT PRINTING OFFICE, 1975-657'591/53Ii5 Region No. 5-1 I
-------
-------
------- |