Summary:

In the article presents effectiveness of sewage treatment in Sewage Treatment Plant in Lipnica Wielka. The domestic sewage follow into the Sewage Treatment Plant in gravity system. The method used for sewage treatment is based on the active sludge method with chemical precipitation of phosphor. The research was carried out in the period from March 2009 to June 2010. The analysis was performed on samples of raw and treated sewage. Three indicators of pollutants were analysed: BOD5, COD, total suspended solids. Furthermore was determined the volume of sewage flowing into the sewage treatment plant.
Basing on the results analysis, effectiveness of BOD5 reduction was defined on the level of 96,23%, COD- 91,42% and total suspended solids - 95,71%. Also it was observed that research of volume of sewage flowing into the sewage treatment plant, were indicated a hydraulically underload.