Gauteng Smallholder November 2016 | Page 41

From page 38 If you use a private laboratory check that it is SANAS 17025 accredited and that it is a member of Agri-Laboratory Association of Southern Africa (AgriLASA). Ask beforehand how they want the sample collected and delivered, but here are general guidelines. Both the sample container and the lid must be scrupulously clean. A 500 ml plastic soft drink bottle with screw top is mostly acceptable. If samples are not dispatched via courier, a 750 ml glass bottle is preferred. Rinse the container three times with the source before taking the sample. In instances where the sample needs to be analysed for micro-organisms, rinse the container and lid three times with hot water at o a minimum 70 C. Then rinse the container three times with the source to be sampled. Fill the container to the brim. It is imperative that a decent, representative sample be taken and the following guidelines are to be followed: K Boreholes: stagnant water in the system should be removed first/pumped out, to ensure that a fresh sample from the hole is taken . K Dams: take the sample as closely to the centre as possible - at least 2m from the edge of the dam. Sample at 25 cm to 50 cm depth. WATER USE Label sample containers clearly by using a permanent marker or by putting the label in a plastic bag and securing it on to the bottle with an elastic band. Store the sample at room temperature, but dispatch to the laboratory as soon as possible. If microorganisms are to be tested for, o cool the sample to 4 C and submit to the laboratory within 24 hours. Special containers are available from laboratories for water samples to be tested for heavy metals. Leaks often appear on the surface some distance from the broken pipe. 39 www.sasmallholder.co.za