Soil protection aims not only to prevent soil contamination, but also to repair and contain damages already done.
The Espoo Environment Department monitors the analysis and rehabilitation of contaminated soils inside the city, promotes repair works, and maintains a record of contaminated sites for city planning and land use purposes, for example. Soil protection is provided for by a number of laws and the environmental protection regulations of the City of Espoo.
Soil is considered contaminated when its harmful substance content clearly exceeds the natural state. Such harmful substances include oils, heavy metals and pesticides, among others. Contamination may pose a risk to human health and the environment, or have an adverse effect on the recreational or utility value of the area. Such sites have usually housed industrial plants, been used as above- or underground landfills, or contained oil or chemical storage units.
There are some 250 sites in Espoo with established or suspected soil contamination. Petrol stations, greenhouses and industrial plants constitute a majority, but there are also former landfills, marinas and old oil storages within the listed sites. The state of the soil needs to be determined at the closing of activities or during a change in use.
Oil and chemical spills and oil tanks
Oil or chemical spills requiring immediate clean-up are reported by calling emergency number 112.
Petrol stations can be contaminated due to leaking underground fuel tanks or during fuelling. Heating oil tanks also involve a risk of soil pollution. All buried oil, fuel and chemical tanks, as well as the above-ground oil and fuel tanks located near important groundwater resources, should thus be inspected regularly every 2–10 years. The condition of any return pipes is examined with pressure tests.
The Espoo Environment Department recommends replacing old oil tanks with new tanks or other heating systems. New underground heating oil tanks or pipelines may no longer be installed near major groundwater basins. New stationary tanks in groundwater areas must be placed above ground and be either double-walled or fitted with a protective basin, and have a single-pipe system from the tank to the burner.
Decommissioned underground oil, fuel or chemical tanks must be cleaned and removed. Oil tank decommissioning is reported with a tank cleaning certificate submitted to the Länsi-Uusimaa Rescue Department. The Espoo Environment Department must be notified of the removal well in advance, as it usually checks the surrounding soil during removal for contaminants.
The tank does not need to be removed if it has been properly cleaned prior to 1 March 2005 and filled with sand or other approved material. The Environment Department may grant an exception from the obligation to remove an underground tank, if the removal is technically very difficult or will result in damage to other property.
In greenhouses, problems relate to heavy metal containing pesticides, persistent organic pollutants (POP), and risks caused by oil heating. Greenhouse soils have been restored in some 15 locations in Espoo.
In landfills, the soil is damaged by toxic waste dumped at the site prior to the existence of hazardous waste disposal plants. The City of Espoo has one existing and 10 decommissioned landfills. Soil in the disused landfills has been examined and some sites have an existing environmental permit to begin remediation. One of the landfills has already been renovated.
The soil in marinas is contaminated by heavy metals, tributyl tin (TBT) and triphenyl tin (TPT) in hull paints, which were generally used to prevent attachment of marine fouling organisms. Tin compounds pass into the bottom sediment and from there via food chain to smaller aquatic organisms and onto fish and other species. The use of tin compounds is now prohibited, and old toxic paints had to be removed from boats by 2008 at the latest.