Automated event sampling for microbiological and related analytes in remote sites: a comprehensive system

Pathogen concentrations are most often monitored during dry weather. Generally in Australia, however, loads mobilised during storms are of more concern. The filling of reservoirs commonly occurs from heavy rain events, and flood inputs may destabilise reservoir hydraulics leading to short-circuiting of contaminates to water supply off-takes. To capture storm events that can occur rapidly in remote locations at any time, automated sampling would seem appropriate. Unfortunately no commercial sampling system appears suitable for collecting multiple large volume samples along a hydrograph. We report here the development of an Event Sampling System (ESS) and associated resources, designed to address the special needs of microbiological sampling and varying event and site characteristics. The resultant ESSs consist of a standardised sampling module, enclosed in housings suited to different circumstances that is currently being field tested at six sites. Sampling module components include ISCO samplers modified to collect 24 ten litre ambient and 24 one litre refrigerated samples at remote sites along with in situ stream data. Essential to this hardware are sample collection and ESS management protocols covering issues such as storm warning, collection team mobilisation, laboratory coordination, ESS commissioning and maintenance. Some issues remain to be addressed, hence the resulting ESSs are seen as prototypes in the development of standardised storm-event based microbiological sampling well suited to remote locations.