Summary:

The paper presents the efficiency of the sewage treatment based on the ex-ample of the sewage treatment plant in Dobczyce. The resarch was based on the analysis of 44 raw sewage and treated sewage from January 2007 to December 2010. Values of five selected pollution indexes were analyzed: BOD5, COD, total suspended solids, general nitrogen and general phosporus. The amount of the transgressions of the admissible index values in relation to the water law permis-sion was defind. The effectiveness of the indexes' decrease In the tested period was analyzed. The carried out research showed the high efficiency of the pollutants amount decrease: BOD5 - 98,9%, COD - 97,6%, total suspended solids - 97,6%, general nitrogen - 89,4%, general phosporus - 97,6%.