4.1 This guide provides persons responsible for designing and implementing wastewater sampling programs with a summary of the types of automatic wastewater samplers, discusses the advantages and disadvantages of the different types of samplers and addresses recommended procedures for their use. The field settings are primarily, but not limited to, open channel flows in enclosed (e.g., sewer) systems or open (e.g., streams or open ditches, and sampling pressure lines) systems.
TABLE 1 Advantages and Disadvantages of Manual versus Automatic Sampling of Wastewater (3)Type
Advantages
Disadvantages
Manual
Low capital cost
Increased variability due to sample handling
Personnel can compensate for various situations
Inconsistency in collection
Personnel can document
unusual conditions
High cost of labor assuming composite or multiple grab samples are collected
Low maintenance
Repetitious and monotonous task for personnel
Extra samples can be collected
in a short time if necessary
Automatic
Consistent samples
Considerable maintenance for batteries and cleaning; susceptible to plugging by solids
Decreased variability caused by sample handling
Restricted in size to the general specifications
Minimal labor requirement for sampling
Greater potential for sample contamination
Capable of collecting multiple
grab and multiple aliquot
composite samples
May be subject to damage by vandals
High capital cost
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 D4687), development of data quality objectives (see Practice D5792), the design of monitoring systems and determination of the number of samples to collect (see Practice D6311), 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 D6233), or sampling and field quality assurance (see Guide D5612). It also does not address sampling groundwater.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3.1 Exception—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.