The rivers Syan and Western Buh,within the water intake basins of which the works of wastes utilization will be done, are right tributaries of the Wisla.
The Wisla is the longest river of the basin of the Baltic sea and Poland. It is formed in the result of merging of the Black and the White Wisla which begin in the Western Beskids. .It falls into the Gdansk bay. Its length is 1090 km, the area of the basin is 139.9 thousand km². The main tributaries are as follows: the Dunajec, the Syan, the Wepr, the Western Buh (right tributaries), the Nida (river), Pylytsia, the Baura (left tributaries).
The Syan is one of he biggest tributaries of the Wisla, and it is 444 km long with total area 16,780 km².It flows out on the edge of the High and Middle Beskids near Urzock pass on the level of 843 meters high, then crosses the Middle Beskid (it crates several lengthy valleys and curves), the Sanicky canyon and mountain foot area, changes the direction from northern to eastern and below Pszemysl it flows to the Northern West through the wide Oversyan valley and below Sandomierz it falls into the Wisla. The river is fed by snow and rain. The main tributaries are: the Solynka, the Oslawa, the Wyslok (left), theVigor, the Vyshnivka, the Liubachivka, the Tanva (right). In the mountainous part on the Syan there have been built Solynskie and Mychkovskie water reservoir and hydroelectric power station.
On the territory of Ukraine there are only sources of the Syan near the village of Syanky, further at the distance of 53 kilometers the river serves as a border between Poland and Ukraine. It flows further through Poland for 390 kilometers.
Outflow of the Syan as for its geographic division belongs to Stryi-Syan highland of Vododilny-Verkhovynsky district of the Ukrainian Carpathians.
On the highland areas of the Syan there were organized a regional landscape park “Nadsyanskyi” with total area of 19,428 ha (Ukraine) and a regional landscape park “The Syan valley” in Poland.
The fact that a big part of the Syan basin belongs to regional landscape parks and that the river has transbpundary character makes the problem of removing from this territory all contaminators, especially those soluble in water such as pesticides, especially burning.
The outflows of the Western Buh are situated near the village Verkhobuzh of Zolochiv rayon in Lviv oblast on the Podilskyi highland. From the village of Ustyluch the river flows along the border between Ukraine and Poland. In Poland the Buh (the Western Buh) falls into the artificial lake Zegrzynskie (earlier – into the Narew river).
The main tributaries are: Bilostok, Luha, Neretva (right), Poltva, Kamianka, Rata (left). The general direction of the river flow is northern-western. Sometimes meanders and former river-beds can be traced. The river-bed is made through overburdens, in some places it cuts through chalk deposits. The width of the river-bed in mean water is 25-70 m, depth 1.1-1.7 m, average speed of the flow is 0.45-0.65 m/sec.
A special feature of geological structure of water scoop of the Western Buh is the fact that above local bases of erosion lie carbonate strata of upper chalk that are represented by fractured and karst limestone and marls by influence of which the formation of salt composition of the river water is determined.
In low water periods, the basin of the Western Buh is fed by numerous sources which flow out of water-bearing horizons of quaternary and upperchalk deposits.
The water regime of the river is characterized by spring floods in abounding in water years, low summer and autumn water level in low-water years, considerable rain floods in summer, sporadic rise of water level in the river-bed in winter. The highest level of water was observed in some years (1910, 1933, 1960, 1922, 1998) in the periods of summer and autumn floods. The height of maximum excess of the level of spring flood in relation to the level in low-water period varies form 1.2m to 2.8m, and in some high-water years to 4.2 m.