Methods for researching a contaminated site

The investigation of soil, groundwater or sediment contamination starts with the preparation of a research plan. The plan presents the methods used to investigate contamination of the site. The research plan includes the collection of historical data, the analysis of environmental conditions and the definition of research methods.

Collecting historical data

Investigating contamination begins with the collection of area activity and historical data so that the research can be targeted at the correct contaminants.  Items to be investigated include: 

  • activity and operating area within the area 
  • substances used in the area 
  • period and volume of the activity 
  • previous research, findings and restoration work
  • information, statements and decisions of the authorities.

Investigating environmental conditions

After the historical data, it is essential to investigate the environmental conditions and potential risk sites within the area: 

  • groundwater areas (water supplies, wells) 
  • surface water 
  • settlements 
  • nature reserves
  • sites protected by the Finnish Heritage Agency
  • other sensitive areas (day care centres, schools).

Research methods

Contamination can be studied using soil, water and sediment samples. Sampling shall be assessed on a case-by-case basis using existing data.

Soil surveys: 

  • trial pit surveys using a shovel or excavator 
  • borehole surveys 
  • ground penetrating radar gauging
  • landfill gas samples

Water surveys:

  • groundwater surveys from a groundwater pipe, well or source
  • surface water samples from, for example, a lake, river or ditch.