The paper considers the influence of economic territories on the quality of water objects and gives hydrochemical indices of the surface runoff from various functional zones of the city. The authors estimate the discharge of pollutants which get into the hydrographic network with the surface runoff.

The purpose of the given research was to investigate the ecology of diverse origin surface runoff, which comes from different territories, taking into consideration some special features of its formation and the pollution degree, as well as to reveal its influence on the hydrographic network pollution.

The studies were conducted in 2006-2012 at the Research Institute of Regional Ecological Problems of the Zhytomyr National Agroecological University and in the Zhytomyr municipal sanitary-and-epidemiological station’s laboratory.

The samples of the surface runoff (SR) were drawn by means of the analysis of rain water in the final pipes. The sampling was carried out by rations (1litre). To obtain the detailed information on the SR, each selected sample was analyzed. In order to systematize the sources of surface water pollution on the territory of the city, the authors selected different functional zones, namely those with predominant multistoried buildings (water intake 1), with predominant individual private houses (water intakes 2-3) and industrial zones (water intake 4).

The sewerage network at all water intakes is fully separate and is represented as gravity-flowing sewers; unloaded storm-water sewage gets without treatment straight into water sources of the city.

The basic typical pollutants of SR from the municipal water intakes are non-soluble substances. Depending on the characteristic of a catch basin their concentration varies from 8 to 150 mg/l. The mean values of indices that characterize dissolvable organic substances (biochemical oxygen consumption – BOC₅, chemical oxygen consumption –COC) in sewage water from the city territories varies within the limits of: by BOC₅—from 10.8 to 27.8 mg O₂/l; by COC – from 34.6 to 67.7 mg O₂/l.

The content of petroleum products in surface water is assessed by the traffic intensity. The value of their content in sewage water from the city’s surface is within 0.02-3.5 mg/l.

As a rule, surface sewage water contains a number of biogenous elements (nitrogen compounds up to 3.4 mg/l; moreover, approximately half of the nitrogen is in the ammonium form, nearly one-third is in the structure of organic compounds, the rest are nitrites and nitrates; phosphorus constitutes nearly 0.5 mg/l).

Among the numerous factors and processes that influence pollutants on their way from a water source to a final pipe the authors revealed the length of the pollutant transport way, which is estimated by the size of a water intake and by its hydrological-and-geological features.

As a result of the investigations conducted, the authors found that the substance concentration in SR from the surface of motor roads varies widely and depends on the traffic density, hydrological conditions, topographic features, industrial pollution sources, etc.

Thus, the concentration of chlorides in the snow on the roadside was 60 to <0.3 mg/l, in the snow cover directly on the roadway it was 365 to 3.8 mg/l, in the road surface water flow -- 4,900 to 7.5 mg/l, and it reached the ceiling values directly at the discharge pipe outlets beyond the range of motor roads (5,800 to 14 mg/l, this being three times higher in comparison with the same indices of surface runoff, which was formed in the agroforest part of the water-shed area. The similar tendency was observed by other indices.

Key words: surface runoff, water, diffusive pollution.