###### Abstract
Among the effects of artificial snow production, there is a prolongation of the snow cover, consequently leading to a shortening of the growing cycle or higher ion concentration in artificial snow than in natural snow, since the water used for its production is most often drawn from rivers [7]. [PERSON] and [PERSON] [7], when examining the effect of artificial snow on the germination of mountain flora, observed that the chemical composition of artificial snow differed largely from the composition of natural snow. Additionally, [PERSON] et al. [8] demonstrated significant differences in the chemical composition of artificial snow (most often produced from water taken from rivers) and natural snow. They also claim that higher concentrations of ions in melt water from artificial snow may affect, for example, plant growth. Moreover, there are some concerns raised by the common use of additives (e.g., ice nucleation active strains of _Pseudomonas syringae_ or ammonium nitrate) in order to optimize freezing of water related to potential health risks such as allergies for, e.g., snowmakers or the use of poor water quality to make artificial snow [9]. The number of ski resorts and ski runs in Poland has rapidly increased in the past few years and Bialka Tatzanska was rated as the best ski resort in Poland since 2012 [10,11]. The popularity of this region results from favorable natural conditions (climate and landscape), culture and constantly expanding infrastructure, including newly constructed ski runs and ski slopes. The calculations conducted by Krzesiwo [12] suggest that in the winter season of 2014/15, only the Kotelnica Bialczanska Ski Resort was visited by about 318,000-342,000 people, of which about 27,000-30,000 were tourists from abroad. However, too high temperatures and too scarce amount of snow are the most important barriers to the development of skiing in Poland, which is why snow cannons, pipelines and retention reservoirs are among the most significant parts of the ski tourism-related infrastructure, as they at least to some extent allow the resorts to become independent of snowfall [10]. The construction and operation of new ski slopes require conducting extensive work and--after launching the ski slope--production of artificial snow, which can be potentially aggravating for the natural environment and surface waters. Such impact, however, has not been examined in detail. [PERSON] et al. [13] conducted a thorough study aimed at assessing the effect of the construction of the considered ski runs on the quantitative and spatial changes in land relief. They found that as a result of the construction of the ski run the catchment elevation was lowered by 0.02 m and they observed changes in the surface runoff patterns in the form of new geometrically regular convergence and divergence zones,as a result of the construction of new drainage ditches. On the other hand, maintaining good quality and conducting both physico-chemical and microbiological analyses of stream water in mountain areas is important for social and economic reasons, as this affects the attractiveness of tourist areas [14]. Therefore, the aim of this study was to assess whether the construction and exploitation of a ski slope, its infrastructure and the associated artificial snow production, had an impact on the aquatic environment in its vicinity. This was achieved by the determination of changes in physico-chemical parameters and the concentration of selected bacteriological indicators of water quality of a Remiaszow stream, which drains the direct vicinity of the ski slope.