During assessments there are various aspects to consider to correctly sample water for an accurate water quality analysis. These aspects include the type of water, the purpose of sampling the water and information regarding the nature of the site.
Water sampling can then easily be separated into five (5) basic steps if information regarding the site and the purpose thereof is obtained and understood.
In terms of sampling rivers or streams for a single sample the following five steps can be used:
Prepare a sterilized bottle prior to sampling of the correct volume required;
Rinse the bottle and cap (without contaminating the interior surface of the cap) vigorously at least two (2) times by water that will be sampled to avoid any potential contamination;
Avoid distributed areas or disturbing the area where the sample will be taken by facing and sampling in an upstream direction or area;
Avoid surface films by completely submerging the bottle (e.g. 25cm below the water surface if applicable);
Fill the submerged bottle by tilting the neck to point slightly upwards to the surface and towards the flow, until completely filled. Replace the cap securely without capturing air bubbles to avoid potential gas exchange.
After completion of these steps ENVASS then submits the samples to the labs with Chain of Custody forms being completed to keep track of sampling, transport, and submission of all samples.