Sandimirov S.S. Catalogue of lakes in the Russian, Finnish and Norwegian Border Area. Finland, Jyvaskyla: Kopijyva Oy, 2008.

The watershed ofLake Samettivatn is located at a distance of 26 km from the Pechenganickel smelter, and is subject­ ed to anthropogenic impacts from the smelter. The main pollutants are sulphur compounds and heavy metals (Ni, Cu, Co, etc.). Despite the fact that emissions from the smelter have dropped to ap­ proximately one third of the peak levels of the late 1970s, the deposition of pol­ lutants still influences the water quality. The average Cu and Ni concentrations are 2.5 |ig/l and 1.8 pg/1, respectively. 2.11.2. Lake bottom sediments The sediments in Lake Samettivatn have relatively low organic matter contents (LOI): in the uppermost 1 cm layer LOI is about 20% (Table 35). Emissions from the smelter affect the concentra­ tions of pollutants (Ni and Co) in the sediments, and the lake is also subject also to pollution by chalcophile ele­ ments, such as Cd, Pb and As. The top 4-5 cm sediment layer is the most polluted (Fig. 48). The contamination factor values for these toxic heavy metals range from 2.0 to 8.9 (Table 35), i.e. the values correspond to moderate, considerable and high contamination. Lead has the highest Cfvalue. The contamination factor values for the other heavy metals correspond to low contamina­ tion. The degree of contamination value (27.9) for this lake corresponds to consider­ able contamination. Lake Layer, cm LOI Cu Ni Zn Co Cd Pb As Hg Cd Samettivatn 0-1 18-19 19.16 21.19 72 133 87 39 82 153 105 14 0.37 0.19 21.1 2.4 9.70 1.81 0.082 0.080 cf 0.5 2.2 0.5 7.4 2.0 8.9 5.4 1.0 27.9 Water colour, deg. 9 8-10 NH4, |ag/l 3 1-5 N03, цд/І 1 1-1 Total N, цд/І 133 117-156 P04, цд/І 1 1-1 Total P, pg/1 4 4-5 Fe, цд/І 17.5 14.0-23.6 Cu, pg/1 2 J> 1.4-4.1 Ni, цд/І L 8 1 .7-2.1 Al, Mg/i I ! 14-24 Pb, цд/і 02 0 . 2 - 0.2 Table 35. The organic matter contents (LOI, %) and heavy metal concentra­ tions (цд/д, dry weight) in the surface (0-1 cm) and pre-industrial (18-19 cm) sediment layers. Cfand Cdare con­ tamination factor and degree of contamination values, respectively. Catalogue ofLakes in the Russian, Finnish and Norwegian BorderArea 99