The crude and processed (pressing, centrifuging, biol. treatment) wastewaters in Gdansk wastewater treatment plant (2004-2006) were analyzed for suspensions, COD, BOD, N and P, org. matter as well as heavy metals (Zn, Cu, Pb, Cd) to det. the plant efficiency. The recycling of reject waters contributed up to 9.7% of daily N and up to 21.7% of daily P inflowing loads in spite of enrichment with hardly degradable org. matter. The recycling resulted also in increasing in exchangeable and recognizable heavy metal fractions.