Catalogue of Lakes in the Russian, Finnish and Norwegian Border Area = [Каталог озер в приграничном районе России, Финляндии и Норвегии] / Nikolay A. Kashulin, Vladimir A. Dauvalter, Sergey S. Sandimirov etc. - Apatity : Institute of the North Industrial Ecology Problems KSC RAS etc., 2008.

3.4.1. Hydrochemistry The water of the lake is slightly acid and has a low mean total mineraliza tion (14.6 mg/l) and low mean alkalin ity (108 |aeq/l). During flood periods the pH of the water drops, but acidification does not develop due to the buffering capacity of the water. The lake has low concentrations of base cations and ani ons, with calcium (average 1.6 mg/l) and bicarbonate (average 6.6 mg/l) predomi nating. The total P and total N concentra tions of water are the main criteria used in assessing the development of water eutrophication. The concentrations and relationships between the species of P and N vary according to the season, and the dynamics is to a greater extent de termined by the level of production and, consequently, the trophicity of the water body. During the vegetation period, the concentrations of total P reach 10 |ig/l and of total N 253 |ig/l. According to the concentrations of mineral nutrients, the lake is classified as mesotrophic. The lake also has col our values and organic matter (up to 5.1 mg/l) and Fe concentrations (mean 335 [ig/1) typical of small water bodies in the region. During high water periods in summer, the concentrations ofP 0 43"and N 0 3~,which determine the lake produc tivity, are low. Although the watershed of Lake Mellalompolo is relatively remote from the “Pechenganickel” smelter (50 km), it is nevertheless subjected to anthropo genic impacts. The water system of the lake receives airborne pollutants emitted by the smelter. The main pollutants are sulphur compounds and heavy metals (Ni, Cu, Al, etc.) Despite the fact that emissions from the smelter have decreased to approximately one third of the maxi mum levels during the late 1970s, the deposition of pollutants still has an impact on the water body. The average Cu, Ni and Al concentrations are 1.2 [ig/1,1.2 [ig/1 and 42 [ig/1, respectively. pH 6.51 6.02-6.82 Electrical conductivity, mS/cm 24 16-41 Ca, mg/l 16 1 . 2 - 2.2 Mg, mg/l 05 0.4-0.7 Na, mg/l 15 1.3-1 .8 K, mg/l 03 0.3-0.4 HC03, mg/l 6& 4.1-12.0 S04, mg/l 2 1 1.9-2.5 Cl, mg/l 1Z 1 .5-2.1 Total mineralization, mg/l 14.6 10.7-18.8 Alkalinity, peq/l 108 68-197 Water colour, deg. 21 10-45 nh 4, Mg/i 23 5-71 N03, цд/І 27 2-90 Total N, |ig/l 253 190-390 Total P, (jg/l 6 3-10 Fe, |ig/l 335 39-1300 Cu, цд/І 1 2 1.1-1.3 Ni, |ig/l 1 2 0.9-2.1 Al, цд/І 42 25-61 Pb, |ig/l 0.18 0.03-0.56 Catalogue o fLakes in the Russian, Finnish and Norwegian BorderArea