ASTM D6538-00(2005)
(Guide)Standard Guide for Sampling Wastewater With Automatic Samplers
Standard Guide for Sampling Wastewater With Automatic Samplers
SCOPE
1.1 This guide covers the selection and use of automatic wastewater samplers including procedures for their use in obtaining representative samples. Automatic wastewater samplers are intended for the unattended collection of samples that are representative of the parameters of interest in the wastewater body. While this guide primarily addresses the sampling of wastewater, the same automatic samplers may be used to sample process streams and natural water bodies.
1.2 The guide does not address general guidelines for planning waste sampling activities (see Guide D 4687), development of data quality objectives (see Practice D 5792), the design of monitoring systems and determination of the number of samples to collect (see Practice D 6311), operational details of any specific type of sampler, in-situ measurement of parameters of interest, data assessment and statistical interpretation of resultant data (see Guide D 6233), or sampling and field quality assurance (see Guide D 5612). It also does not address sampling groundwater.
1.3 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact ASTM
International (www.astm.org) for the latest information.
Designation:D6538–00 (Reapproved2005)
Standard Guide for
Sampling Wastewater With Automatic Samplers
This standard is issued under the fixed designation D 6538; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope D 3856 Guide for Good Laboratory Practices in Laborato-
ries Engaged in Sampling and Analysis of Water
1.1 This guide covers the selection and use of automatic
D 4687 Guide for General Planning of Waste Sampling
wastewater samplers including procedures for their use in
D 4840 Guide for Sampling Chain-of-Custody Procedures
obtaining representative samples. Automatic wastewater sam-
D 5088 Practice for Decontamination of Field Equipment
plers are intended for the unattended collection of samples that
Used at Nonradioactive Waste Sites
are representative of the parameters of interest in the waste-
D 5283 Practice for Generation of Environmental Data
water body. While this guide primarily addresses the sampling
Related to Waste Management Activities Quality Assur-
of wastewater, the same automatic samplers may be used to
ance and Quality Control Planning and Implementation
sample process streams and natural water bodies.
D 5612 Guide for Quality Planning and Field Implementa-
1.2 The guide does not address general guidelines for
tion of a Water Quality Measurement Program
planning waste sampling activities (see Guide D 4687), devel-
D 5792 Practice for Generation of Environmental Data
opment of data quality objectives (see Practice D 5792), the
Related to Waste ManagementActivities: Development of
design of monitoring systems and determination of the number
Data Quality Objectives
of samples to collect (see Practice D 6311), operational details
D 5851 Guide for Planning and Implementing a Water
of any specific type of sampler, in-situ measurement of
Monitoring Program
parameters of interest, data assessment and statistical interpre-
D 5956 Guide for Sampling Strategies for Heterogeneous
tation of resultant data (see Guide D 6233), or sampling and
Wastes
field quality assurance (see Guide D 5612). It also does not
D 6233 Guide for Data Assessment for Environmental
address sampling groundwater.
Waste Management Activities
1.3 The values stated in SI units are to be regarded as the
D 6311 Practice for Generation of Environmental Data
standard. The inch-pound units given in parentheses are for
Related to Waste Management Activities: Optimizing
information only.
Sampling Design
1.4 This standard does not purport to address all of the
E 856 Definitions of Terms and Abbreviateions Relating to
safety concerns, if any, associated with its use. It is the
Physical and Chemical Characteristics of Refuse Derived
responsibility of the user of this standard to establish appro-
Fuel
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
3. Terminology
2. Referenced Documents 3.1 composite sample, n—a combination of two or more
2 samples. (D 1129)
2.1 ASTM Standards:
3.2 representative sample, n—a sample collected such that
D 1129 Terminology Relating to Water
it reflects one or more characteristics of interest (as defined by
D 3694 Practices for Preparation of Sample Containers and
the project objectives) of a population from which it was
for Preservation of Organic Constituents
collected. (D 5956)
3.3 sample, n—a portion of material taken from a larger
This guide is under the jurisdiction of ASTM Committee D34 on Waste quantity for the purpose of estimating properties or composi-
Management and is the direct responsibility of Subcommittee D34.01.01 on
tion of the larger quantity. (E 856)
Planning for Sampling.
Current edition approved July 1, 2005. Published August 2005. Originally
4. Significance and Use
approved in 2000. Last previous edition approved in 2000 as D 6538-00.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4.1 This guide provides persons responsible for designing
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
and implementing wastewater sampling programs with a sum-
Standards volume information, refer to the standard’s Document Summary page on
mary of the types of automatic wastewater samplers, discusses
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact ASTM
International (www.astm.org) for the latest information.
D6538–00 (2005)
the advantages and disadvantages of the different types of and provide a history of variation. Grab samples are appropri-
samplers and addresses recommended procedures for their use. ate when samples are needed to:
6.1.1 Characterize an effluent that is not continuous,
5. Automatic Versus Manual Sampling (1, 2)
6.1.2 Provide information about instantaneous concentra-
5.1 The advantages and disadvantages of manual and auto- tions of pollutants,
matic sampling are summarized in Table 1. The decision as to 6.1.3 Allow collection of samples of varied volume,
whether to use manual or automatic sampling involves many 6.1.4 Corroborate composite samples,
considerations in addition to equipment costs. In general, 6.1.5 Monitor parameters not amenable to compositing (for
manual sampling is indicated when infrequent samples are example, pH, temperature, dissolved oxygen, chlorine, purge-
required from a site, when biological or sediment samples, or able organics (unless a specialized sampler is used), oil and
both, are also required, when investigating special incidents, grease and others specified by a permit which may include
where sites will not allow the use of automatic devices, for phenols, sulfites and hexavalent chromium).
most bacteriological sampling, where concentrations remain 6.1.6 Characterize a waste stream in detail where rapid
relatively constant, etc. The use of automatic samplers is fluctuations of parameters occur (sequential grabs).
indicated where frequent sampling is required at a given site, 6.2 Composite Samples—Composite samples are collected
over time, either by continuous sampling or by mixing discrete
where long-term compositing is desired, where simultaneous
sampling at many sites is necessary, etc.Automatic sampling is samples, and represent the average characteristics of the waste
stream during the compositing period. Composite samples are
often the method of choice for storm-generated discharge
studies, for longer outfall monitoring, for treatment plant collected when stipulated in a permit, when average pollutant
concentration during the compositing period is to be deter-
efficiency studies, where 24-h composite samples are required,
etc. The user should review 7.1.22 before selecting manual or mined, and when wastewater characteristics are highly vari-
able. There are four types of composite samples.
automatic sampling.
6.2.1 Time Composite Samples—This method requires dis-
6. Types of Samples Collected by Automatic Samplers
crete sample aliquots be collected in one container at constant
6.1 GrabSamples—As defined under the U.S. Environmen- time intervals. The method is appropriate when the flow of the
streamisconstant(flowratedoesnotvarymorethan 610 %of
tal Protection Agency’s (EPA) National Pollutant Discharge
Elimination Program, grab samples are individual samples the average flow rate (4)) or when flow monitoring equipment
is not available. The EPA allows time-proportional sampling
collected over a period of time not exceeding 15 min and are
representative of conditions at the time of sampling (4). Grab and requires samples be collected every 15-min, on average,
samples are sometimes also called individual or discrete over a 24-h period.
samples (5). Sequential grab samples are a series of grab 6.2.2 Flow-Proportional Composite Samples—There are
samples collected at constant increments of either time or flow two methods used for this type of sample (4). The most
commonly used method with automatic samplers collects a
constant sample volume at varying time intervals proportional
to stream flow based on input from a flow monitor (for
The boldface numbers given in parentheses refer to a list of references at the
end of the standard.
example, a 200-mL aliquot is collected for every 5000 L of
flow). In the other flow-proportional compositing method, the
TABLE 1 Advantages and Disadvantages of Manual versus
sample is collected by varying the volume of each aliquot as
Automatic Sampling of Wastewater (3)
the flow varies, while maintaining a constant time interval
Type Advantages Disadvantages
between the aliquots.
6.2.3 Sequential Composite Samples—A sequential com-
Manual Low capital cost Increased variability due to
sample handling
posite sample is composed of a series of short-period compos-
Personnel can compensate for Inconsistency in collection
ites, each of which is held in an individual container, for
various situations
Personnel can document High cost of labor assuming example, four sample aliquots are composited (one every 15
unusual conditions composite or multiple grab
min) to form hourly composites (4). The 24-h sequential
samples are collected
composite is then manually made by compositing the indi-
No maintenance Repetitious and monotonous
task for personnel vidual 1-h composite sample.
Extra samples can be collected
6.2.4 Continuous Composite Samples—This method re-
in a short time if necessary
quires that the sample be collected continuously at a constant
Automatic Consistent samples Considerable maintenance for
rate or proportional to flow (4). This method is seldom used
batteries and cleaning;
with automatic samplers.
susceptible to plugging by
solids
7. Attributes of Automatic Samplers
Decreased variability caused by Restricted in size to the general
sample handling specifications
7.1 The EPA (6) developed a list of attributes of the ideal
Minimal labor requirement for Greater potential for sample
automatic sampler for their use and EPA Region 4 (7) and
sampling contamination
Capable of collecting multiple May be subject to damage by others (3) have noted other important attributes. These at-
grab and multiple aliquot vandals
tributes and requirements may be specific to EPA’s use and
composite samples
were primarily directed at suction lift type automatic samplers.
High capital cost
Not all these sampler characteristics will be important to all
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact ASTM
International (www.astm.org) for the latest information.
D6538–00 (2005)
users but their consideration may guide persons selecting 7.1.22 Other Factors—Other factors (3) that should be
automatic samplers. The desirable features of automatic sam- considered in selecting an automatic sampler are the:
plers listed below have been summarized and combined from 7.1.22.1 Expected variation in water or wastewater compo-
the referenced documents. sition with time,
7.1.1 Capable of AC/DC operation with adequate dry bat- 7.1.22.2 Variation of flow rate with time,
tery energy storage for 120-h operation at 1-h sampling 7.1.22.3 Specific gravity of the liquid
intervals. 7.1.22.4 Concentration and density of suspended solids of
7.1.2 Suitable for suspension in a standard manhole yet still interest,
accessible for inspection and sample removal.Asecure harness 7.1.22.5 Presence of floating materials,
or mounting device if the sampler is placed in a sewer. 7.1.22.6 Characteristicsofthesitewherethesamplerwillbe
7.1.3 Total weight, including batteries, less than 18 kg. placed,
Compact and portable enough for one-person installation. 7.1.22.7 Range of intended use (a permanent site or travel-
7.1.4 Sample collection interval adjustable from 10 min to 4 ing sampler),
h. 7.1.22.8 Skill level required for installation and operation of
7.1.5 Capable of collecting a single 9.5-L (2.5-gal) sample the sampler, and
7.1.22.9 The level of accuracy desired.
and/or collecting 500-mL (0.13-gal) discrete samples in a
minimum of 24 containers.The individual sample aliquot must
8. Types of Automatic Samplers (1,2,3)
be at least 100 mL.
8.1 There are three main types of automatic samplers,
7.1.6 Capable of multiplexing repeated aliquots into dis-
suction lift, pressure or forced flow, and mechanical. Each has
crete bottles.
its advantages and limitations and all types are available in
7.1.7 One intake hose with a minimum inner diameter of
models designed to preserve samples via cooling (iced or
0.64 cm (0.25 in) and a weighted, streamlined intake screen
refrigerated).While all automatic samplers can collect samples
which will prevent accumulation of solids.
through time, some samplers are designed to be triggered by
7.1.8 Intake hose liquid velocity adjustable from 0.6 to 3
inputs from online devices measuring flow, pH, temperature,
m/s (2.0 to 10 ft/s) with dial setting.
conductance, etc., and collect samples under specific condi-
7.1.9 Minimum lift capacity of 6.1 m (20 ft).
tions (for example, pH >9.0).
7.1.10 Explosion proof construction.
8.2 Suction Lift—Suction lift devices can be further subdi-
7.1.11 Watertight exterior case to protect components in the
vided into peristaltic and vacuum type samplers. Peristaltic
event of rain or submersion.
pump devices are the most commonly used type in the United
7.1.12 Exterior case capable of being locked, including lugs
States and use a rotating head to pinch a flexible hose creating
for attaching steel cable to prevent tampering and to provide
a vacuum to transport the sample to the container. Vacuum
security.
devices (8) are more popular in Europe and use a vacuum
7.1.13 An integral sample container compartment capable
pump to transport the sample to the sample container. Suction
of maintaining samples at 4 to 6°C for a period of 24 h at
liftsamplersareportable,versatileduetotheirlightweightand
ambient temperatures up to 38°C.
can purge the transport line between samples. Their main
7.1.14 Capable of operating in a temperature range from–
limitationisthattheirliftcapacitywhichisclaimedtorangeup
10 to 40°C with the exception of the intake hose.
to 9 m but may be significantly less. Also, since suction lift
7.1.15 A purge cycle to flush the sample intake tubing
devices use a vacuum to transport samples, they cause some
before and after each collection interval, and a mechanism to
degassing of the sample and are generally unsuitable for
sense and clear a plugged sample line and then
...
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