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3.4.12 Real time collection of data (samples)

The collection of real-time data is a developing area, with improvements in instrumentation and miniaturisation of technologies. The fast gathering, interpreting, and sharing of data facilitates support for real-time decision making. The range of technologies supporting real-time measurements includes:

  • Field analytical instrumentation.
  • In-situ sensing systems.
  • Geophysics.
  • Computer systems that assist project planning, store, display, map, manipulate and share data.

For real-time radioactive data collections see also Section 3.6.1.

Geophysical acquisition of subsurface real-time data is discussed in Section 3.6.2, and cone penetrometer test geo-environmental probes are cited in Table 3.43, Techniques for intrusive sampling.

Real-time monitoring is suitable for other forms of physico-chemical parameters. The use of data loggers to record groundwater fluctuations is an established technology, but other parameters could be monitored, particularly for water quality, as the technologies develop, offering:

  • High frequency data collection.
  • Smart technology enabling conditional water sampling.
  • In-situ calibration.
  • Data retrieval via telemetry/mobile phone links.

Tests for chemical or radioactive contaminants can be carried out on-site, as opposed to sending samples to a laboratory for analysis. In general, field tests provide indicators of contaminant concentrations, rather than actual concentrations, and results need to be verified with a small population of laboratory analyses. Examples of commonly used field tests for soils are:

  • Immuno-assay techniques (measures relative concentrations of selected organics, e.g., VOCs, PAH).
  • Headspace analysis (FID or PID measurement of volatiles).
  • Field chromatography.
  • Biosensors (e.g., enzyme systems, antibodies, deoxyribonucleic acid or microorganism).
  • Colourimetric test strip (wet chemistry, but not immuno-assay).
  • Mobile XRF for metal analyses.
  • Membrane interface probe.

Samples taken in the field may also be analysed in a mobile laboratory to obtain higher detection limits, but care should be taken to protect against high background, particularly for radioactivity analyses.

The real advantage with collection of real-time data is that it is quick and often relative cheap. It also provides an instant result and can be used to direct investigation immediately. However, the quality of real-time data should always be assessed against the quality criteria set for the project. Back-up off-site laboratory verification will be required for radioactive and non-radioactive contaminants, particularly where the data gathered is sent to the regulators.