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

Abstract

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.

Microbiological monitoring and automated event sampling at karst springs using LEO-satellites

“…This confirms a previous report that microbiological cross contamination or carry over for faecal indicators (FI) from corresponding previous sampling cycles are expected below 2%, if dead zones are removed and flushing cycles before each sampling interval are to be applied (Roser et al 2002). However, the automated microbial sampling could be improved by cooled sampling devices, although the surrounding temperature in the spring tapping of our monitored springs was not appreciable higher as the water temperature (approximately 5.5°C) during summertime.…”

“…Additionally, the described system is not limited to E.coli as a general parameter of recent faecal pollution and may thus be extended to other appropriate microbial indicators and tracers. In this case, modification may be necessary in order to increase and adapt required sampling storage volumes (Roser et al 2002). …”

Catchment process affecting drinking water quality, including the significance of rainfall events, using factor analysis and event mean concentrations

“…It could therefore be hypothesised that this indicator needs a high rainfall intensity to be mobilised. Events 2 and 4 are also preceded This is similar to findings reported by Roser et al (2002).…”

“…Capturing a storm in this way could provide an indication as to whether there is a flush of contaminants from the catchment, as is reported in urban storm water literature (Lee et al 2002;Taebi & Droste 2004), or whether once mobilised there is a seemingly endless supply of pollutants, as reported by Roser et al (2002). This sampling regime is similar to the sampling regime in event 1.…”

Automated Sampling Procedures Supported by High Persistence of Bacterial Fecal Indicators and Bacteroidetes Genetic Microbial Source Tracking Markers in Municipal Wastewater during Short-Term Storage at 5°C

“…This deficiency can potentially lead to false-negative results or underestimation of (10)(11)(12)(13). Nonetheless, several studies have demonstrated the potential of automated sampling procedures for pollution microbiology (2,(14)(15)(16)(17). For example, autosampling was used to elucidate previously unobserved microbial fecal pollution dynamics in alpine water resources, results that had significant implications for water quality management (14,18).…”