WATER POLLUTION IMPACT OF HUMAN ACTIVITIES University of Veterinary Medicine and Pharmacy in Košice, Slovak Republic WATER POLLUTION IMPACT OF HUMAN ACTIVITIES IN THE CATCHMENT OF THE RIVER HORNAD Miňo I., Sasáková N., Hromada R., Korytár Ľ., Holotová E. Introduction One of the major challenges of the future is to ensure the supply of clean water to the world population. Population growth, water pollution and the increasing water consumption per capita have a strong impact on water quality. In addition, expansive climate changes and change in land use influence global and regional water cycles and thus question the medium and long-term availability of water." This study deals with water pollution due to human activities in the catchment area of the river Hornad. Pollution of surface water: Surface flows in the territory belongs to the basin Canyon. Surface water quality is assessed according to STN 75 7221 "Classification of surface water", which assesses water quality in 8 groups of indicators: A. indicators of oxygen regime, B. The basic physical-chem. indicators, C. nutrients, D. biomarkers, E. microbiological indicators F. micropollutants. G. toxicity. H. radioactivity. Surface water, according to water quality to be assigned from first class (very clean water) to the fifth quality class (very highly polluted water). Hornad - in Kosice is heavily loaded flow of the river Hornad discharged by sewage and industrial waste water pollution of the city. Amount of coliform bacteria is indicator of the wather quality and it´s high amount ranks the river Hornad in to IV. quality class. That points to a lack respectively. no cleaning sewage water in settlements over the study area. Water quality in the other indicators is in the II. - III. class. Pollution of ground water: Territory extends the important water management area "the river sediments." Monitoring network of groundwater quality in the area is ensured by Slovak Hydrometeorological Institute. Monitoring network consists of 10 wells which are drilling at a depth of 8-14 m, and collecting the water from quaternary sediments. The most common exceedance occurs in levels of Fe and Mn as a result of unfavorable oxygen conditions. Were also measured high levels of sulphate, nitrate and chloride. In case of trace elements there were measured limit concentrations of aluminum. Sources of water pollution: The main problems influencing the the quality and groundwater and surface water are eutrophication processes (increased content of biogenic elements P and N) content of heavy metals and the content of specific organic compounds in aqueous medium. mentioned problems are linked to: • industrial production - produced by poor cleaning of industrial waste water, respectively. poor technology, • agriculture - particularly the use of agrochemicals, • Insufficient treatment of sewage from towns and villages. Sources of pollution that negatively affect the quality of water can be classified according to their nature and operation into two categories: • point sources of pollution that significantly affect the quality of water in surface streams, stream sediments and accordingly the quality of groundwater have concentrated wastewater discharges into recipients and in this sources we can determine the aetiology and basic characteristics of the discharged waste water, • diffuse sources of pollution that are not included among the registered pollution sources and which ones are wild landfills, areas of agricultural production, field dunghills, silage pit, airports, workshops, but especially mass objects livestock are less controllable, measurable in contrast to point sources pollution are less targeted, registration is more difficult and it is more problematic to measure the effect to environmnet, summary effect is only an estimate. The greatest danger from diffuse sources is the loading of nitrogen and phosphorus. Excess nitrates and phosphorus in water sources significantly contribute to eutrophication and the degradation of surface and groundwater. The total quantity of waste water and pollution in the Hornád basin has fallen. Also significantly decreased the amount of organic pollution discharged wastewater (BSK5, NL). Positive developments were also recorded concentrations of NELUV nitrates. This reduction was caused by major industrial and municipal sources of pollution. Proposed measures to reduce the current water pollution: The areas with the legislative protection of nature, elements of environmental system are to be considered in human intensively used land for isolated islands and must be protected as natural areas, which are of great importance for the stability of the landscape and biodiversity, but also to protect the geological substrate , soil and water resources Implement the regulation of watercourses and flood protection measures by environmentally acceptable form Preserving and protecting wetlands and wetland ecosystems that have a positive effect on the environment Reinforcing the banks of watercourses, which favorably affect the quality of watercourses. This study was supported by Cultural and Educational Grant Agency of the Ministry of Education of the Slovak Republic, Science, Research and Sport of the Slovak Republic KEGA no. 003UVLF-4/2016.