Epsilon Archive for Student Projects

Abstract

The county administration asked LKAB to make an inventory of possibly contaminated sites caused by their mining activity. The inventory should be performed according to the MIFO model, a method from SEPA which is used to assess a contaminated site. The first phase involves collection of information through interviews and site inspections and in phase 2 a general survey with field sampling is conducted.

LKAB started the work with the first phase of the survey during 2003. During this project the information collected in Phase 1 was evaluated and 16 of the sites were chosen to proceed to MIFO Phase 2 (six sites in Kiruna, and 5 sites respectively in Svappavaara and Malmberget). The sampling of these 16 sites was performed during week 27 2004. The planning and the sampling were done together with MRM in Luleå and the soil samples were sent to Analytica in Luleå for laboratory analysis.

The sampling was primarily done with a one meter long screw drill, powered by GeoMaskin 75. This method was also used to drill holes for groundwater pipes. Other methods used were: moraine drill (powered by GeoMaskin 75), sampling pit dug by excavator and manual sampling on the soil surface with a spoon. The information from phase 1 was used to make individual sampling plans for each site. In order to design a sampling plan choices are made regarding: sampling pattern, number of samples, sampling method, etc. Two of the 16 sites could not be sampled according to the plan: The transformer place (object 8) and Present Refuelling place (object 14). The coarse top material at the transformer place could not be penetrated with the equipment at the site and too many wires in the ground made it impossible to take soil samples at the Present Refulling place.

At iron ore mines it is mostly the activities around the mine such as workshops, refuelling places, junkyards etc. that causes most of the pollution and compared to sulphide mines there are relatively few heavy metals. The heavy metals found at the contaminated sites in this survey were mostly arsenic and mercury, but also some zinc, copper lead, cadmium and nickel. The two junkyards (object 1 and object 15) and The former scrap collection place (object 13) are the three sites where heavy metals had high concentrations. These objects also have the most complex contamination situation with both heavy metals and organic compounds.

The most contaminated sites at LKAB’s industrial areas have high concentrations of aliphatic hydrocarbons and in some cases low concentrations of PAH. The highest concentrations are found on The oil pits (object 7), but also at other sites where oil and diesel have been handled. These sites include areas where oil has been temporary stored, areas such as The blue barn (object 2), The boiler room, PC 5 (object 3) and KCK (object 12), but also places where the transformers are (object 8 and 16) as well as the refuelling place in Kiruna (object 5).

During this survey no traces of PCB, solvents and chlorinated hydrocarbons have been found. And no high concentrations of pollution were detected in the three groundwater pipes which were installed (two groundwater pipes at The industrial disposal site (object 6) and one pipe at The junkyard (object 15)).