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Sewage sampling |
Bacteriophage isolation sample types
Influent
Influent wastewaters are ideally sampled at locations of highly turbulent flow to ensure good mixing; however, the most desirable location is not always accessible. Input wastewater sampling locations that are preferable include:
- The upflow siphon following a comminutor (in absence of grit chamber);
- The upflow distribution box following pumping from the main plant wet well;
- Aerated grit chamber;
- Flume throat;
- pump wet well when the pump is operating, or
- downstream of preliminary screening. When possible, influent samples should be collected upstream from sidestream returns.
Effluent
Effluent samples should be collected at the site specified in the permit, or if no site is specified in the permit, at the most representative site downstream from all entering wastewater streams prior to discharge into the receiving waters. If a conflict exists between the permittee and inspector regarding the source being sampled or the location of the most representative site, Site Selection for Wastewater Sampling.
Pond and Lagoon
Sampling Generally, composite effluent wastewater samples should be collected from ponds and lagoons. Even if the ponds or lagoons have long retention times, composite sampling is necessary because ponds and lagoons have the tendency to have flow paths that short circuit, which changes the designed detention time.
How to collect the sample?
The simplest method is to collect sewage water in a sterile falcon tube (45-50ml) and then pour it into a well-labeled borosilicate container (even a falcon tube can work) and tighten the container’s cover to prevent leakage. Transfer the container to the cool box so that it can be transported to the laboratory.
NOTE: Don’t forget to put on PPE as described in detail here