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.
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 | 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 |
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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 | 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.