, 2012). Although surface rainwater runoff has frequently been investigated in many countries, little attention has been

paid to urban snowmelt runoff (Buttle 1988). In countries with a moderate continental climate, winter surface runoff quality is influenced primarily by litter and rubbish from streets, soil and pavement erosion, emissions from vehicles and industry, road de-icing composites, street cleaning, salting and snow removal etc., as well as the weather conditions (Sujkova et al. 2012, Shhukin et al. 2012). Up to 60% of the annual pollutant load related to surface runoff originates from the winter period, because pollutants Belnacasan manufacturer are accumulated in the snowpack and then released during intermittent and final snowmelt (Marsalek 2003). In cities where the surface runoff drainage system was designed in the mid-20th century, the common practice has been to discharge the runoff directly into watercourses, since for a long time urban surface runoff was not considered harmful to the environment. In the city of Brest, the surface runoff from the majority of drainage collectors is discharged directly into the River Mukhavets. The Mukhavets is the main river of Brest Polesye, a watercourse important for the socio-economic development of the region. Four towns are situated on the banks

of the Mukhavets, and the river provides a water supply, shipping, fishing and recreation for their populations.

The river see more is also the main recipient of wastewaters (Volchek et al. 2005). Furthermore, the Mukhavets is a tributary of the trans-boundary Western Bug, a river belonging to the Baltic however Sea catchment area. This means that the contaminants entering the Mukhavets contribute to the total amount of pollutants carried to the Baltic Sea by river systems. The aim of this paper was to study the inorganic constituents of snow and snowmelt runoff in urban areas as exemplified by the city of Brest, and to indicate the components that could pose a potential environmental threat. Accordingly, the concentrations of inorganic ions such as chloride, phosphate, nitrate and ammonium, heavy metals (HM) – Pb, Cu, Mn, Zn, Fe, Ni, Cr – as well as total suspended solids (TSS) and pH were determined in samples of snow and snowmelt runoff collected from December 2012 to April 2013. To evaluate the impact on surface waters, all the results were compared with the national regulations for surface waters – the maximum permissible concentrations (MPC) for fish breeding waters (Regulation No. 43/42). TSS concentrations were compared with the national regulation for urban surface runoff discharges (TCGP, 2012 – Technical Code 17.06-08-2012 (02120)), because the regulation for fish breeding waters does not limit the concentration of TSS, but only states its maximum permissible increase after wastewater discharges.