The traditional way of dealing with manure - storage, transportation, spreading in the fields - is currently applied very successfully, but is economically very expensive. People complain about very unpleasant smells, which are caused by gasses (indole, merkaptanas, hydrogen sulphide, ammonia) being released from the manure. Scientists are searching for other ways of handling manure which try to convert it to less harmful substances, reduce its odour and at the same time make it thicker by extracting its water content. The aim of our work was to evaluate the composition of slurry after processing it mechanically, and to test the effectiveness of the application of new coagulants and flocculants on its clarification. Fresh liquid manure from 'Sajas' pig complex(Kelme district) and the liquid manure treated in biogas reactors from Lekėčiai pig complex (Šakiai district) was used for research (2006-2008). Anionic coagulants such as aluminium chloride (Al2Cl), ferrous chloride (Fe2Cl) and pollycrilamide cationic flocculant 'Magnofloc 1011' were applied to clarify manure. 40-44% of organic pollutants can be removed from the aerated sewage under constant processing by coagulants and flocculants. The best result in pollutant removal from sewage is achieved when it is processed with 1.5 kg mE-3 norm of aluminium saline (AlCl) and 3.0 g mE-3 norm of flocculant 'Magnofloc 1011'.

The paper deals with the analysis of ground water quality when slurry is applied on crop rotation fields. The investigations were carried out in Juodkiskis study object of the Lithuanian Institute of Water Management in 1995-1998. According to the average concentrations, the quality of ground water samples taken from the borehole arranged in Juodkiskis test field was good compared with hygienic rates for drinking water. All samples taken for the estimation of ammonia and nitrate nitrogen amount were of good quality. However, nitrate-N concentration increased to 5.5-5.6 mg lE-1 in some periods. Having compared actual phosphate phosphorus concentrations with the allowable ones it may be confirmed that ground water is not polluted with phosphates as phosphate phosphorus concentrations did not reach P-load permissible for drinking water. Considering the correlation connection between ground water level and chemical compounds concentrations, it was determined that ammonia nitrogen and phosphorus compounds concentrations were influenced by ground water level fluctuations (correlation coefficient r = 0:54 and r = 0:62). (Given r values correspond to the reliability criterion tactual is greater than ttheor95%). Lower ground water levels in a borehole determine higher N - NH4**+, P - PO4**- and Ptotal concentrations. No relation between nitrate nitrogen (N - NO3**-), Ntotal and K**+ and ground water level fluctuations was determined.