Christchurch City Council currently carry out manual grab sampling of first flush stormwater in the city’s urban waterways. This requires samplers to be on site during rainfall events, which do not always occur at times suitable for field sampling. Bioresearches have been commissioned to carry out a field test of an automated stormwater sampler. The sampler can be installed in a target waterway prior to rainfall occurring and then retrieved at a later time, once it has captured the first flush water. However, as this method is currently untested in Christchurch and relatively new to New Zealand, Bioresearches is also undertaking the traditional grab sampling at the same time in order to evaluate the results and determine if the automatic sampler generates better or different results compared to the traditional method.
Once sampling has been completed, Bioresearches will be able to make a recommendation regarding the continued use of the automatic samplers. If the decision is made to continue using them, guidance on their installation and use will be provided.