How to take a Microbial Water Analysis Sample
Materials Required: Alcohol wipes, Cooler with gel ice packs, Rubber gloves, Water resistant marker, Sterile sample containers with sodium Hypochloriteor as necessary
ProcedureSamples must be taken from locations that are representative of the water source, treatment plant, storage facilities, distribution network, and points of use. In selecting sampling points, each locality should be considered individually; however, the following general criteria are usually applicable:
- Sampling points should be selected such that the samples taken are representative of the different sources from which water enters the system.
- These points should include those that yield samples representative of the conditions at the most unfavorable sources or places in the supply system, particularly points of possible contamination such as unprotected sources, loops, reservoirs, low-pressure zones, ends of the system, etc.
- Sampling points should be uniformly distributed throughout a piped distribution system, taking population distribution into account; the number of sampling points should be proportional to the number of links or branches.
- The points chosen should generally yield samples that are representative of the system as a whole and of its main components.
- Sampling points should be located in such a way that water can be sampled from reserve tanks and reservoirs, etc.
- There should be at least one sampling point directly after the clean-water outlet from each treatment plant. A 1 litre sample in a sterilized plastic bottle is required for this analysis (sterilized bottles are provided by the laboratory on request). Label each bottle with the Client name, Location, Date and Time before proceeding to the site of sample collection.