In Norway there are numerous sites where land has become contaminated by human activities such as industry, chemical and oil spills and waste disposal. Contamination can also occur naturally as a result of the geology of an area. An example of this is alum shale and other rock types that contain sulphur which are common in the south-eastern parts of Norway. 

Locations with contaminated ground are often related to old landfills containing hazardous waste or industrial sites contaminated by hazardous chemicals. Contamination has been caused by both public enterprises and private companies. In many cases, contamination is caused by operations or waste disposal methods that are not considered acceptable today.

The map shows contaminated sites in Oslo.

The Climate and Pollution Agency has identified over 3500 contaminated sites where the ground is believed to be contaminated. Some of these sites have been remediated.  In November 2011 356 sites were identified as heavily contaminated and in need of remediation (impact level 3).

The Climate and Pollution Agency has created a database that gives information about sites where there is contaminated ground or reason to suspect contamination. The database gives information on the site, type of contamination and assessments and measures taken on the area. There is also a possibility to report sites where one suspects that the ground is contaminated.

• Database "Grunnforurensning"

Contamination from earlier generations can result in the dispersal of hazardous chemicals in soils, ground water and surface water. At some sites, such contamination may represent a risk to human health, cause irreversible environmental damage or make the land unsuitable for some ranges of use.

Area contaminated with creosote. Some places are so heavily contaminated that plants are not able to grow there. Photo: Asplan Viak

In cases where the contamination of the soil might pose a risk, the land has to be restored to a state in which it is suitable for use. The Norwegian government has been working with the remediation of contaminated sites for several decades.

The work has so far focused on 600 of the most contaminated known sites. Full remediation of approximately 150 of these has been ensured. The state of the remaining sites has been mapped and assessed for the need for remediation based on the risk for human health and/ or the environment. The remediation of some of these sites has already started and the government plans to finish the remediation of the remaining sites by 2012.

Over a thousand sites where there is reason to believe that the ground is contaminated still remain. The Climate and Pollution Agency is working on getting a more complete overview over these sites.

We have identified several types of industry or activities that have a high probability of contaminating the soil. These include petrol and filling stations, mining installations, the galvanic industry and large green-houses. In most cases the present land usage does not represent a severe danger to human health or the environment. However, these sites still need to be followed up, because a change in land usage could lead to health risks or to the leakage of hazardous substances.

Remediation of contaminated soil in day-care centers

The Norwegian government wishes to reduce the amount of hazardous substances a child is exposed to. An “Action Plan” to clean up hazardous substances in children’s outdoor environment was introduced in 2006 and includes the investigation of contaminated soil in day-care centers in the ten largest cities and five big industrial areas in Norway.

The Climate and Pollution Agency coordinates the project, makes guidelines and gives financial support while the actual work is done by the municipalities. By the end of 2008 the soil in almost 2000 day-care centers had been assessed.

The results show that there is a need for the removal of polluted soil or treated wood in nearly 70 percent of the investigated day-care centers. This is largely due to the use of CCA-treated wood around sandboxes.

In Norway, the use, import or selling of treated wood that contains the heavy-metals chrome or arsenic (CCA) is prohibited. The soil is very often contaminated by aresenic in day-care centers that used CCA-treated wood before this regulation entered into force in 2002.

Remediation due to soil pollution is needed in almost 30 percent of the investigated day-care centers. Lead is the most common contaminant followed by benzo(a)pyrene, arsenic and polycyclic aromatic hydrocarbons (PAH).

The contamination is most likely due to industrial activities, traffic or the use of contaminated soil in landscaping. The most important source for arsenic contamination in day-care centers is the use of CCA-treated wood around sandboxes. The CCA leaks arsenic to the soil and children are also exposed by touching the treated wood.

Use of CCA-trested wood around a sandbox in a Norwegian day-care center. Photo: Norwegian Geological Survey

The results of the investigation was followed up in 2010 and 2011.  In day-care centers where the contamination in the soil exceeded the soil quality criteria set for day-care centers (see table) the soil was removed and replaced with documented clean soil. CCA-treated wood around sandboxes was also removed and replaced with alternatives without arsenic.

CCA- treated wood in other installations is to be oil varnished every second year until they are removed.