Pitka voda najbitniji je resurs na našoj planeti i osnova svakog ljudskog, životinjskog i biljnog života. Važnost očuvanja voda i okoliša postaje sve veći prioritet jer su se nakupile godine, desetljeća i stoljeća u kojima su ih ljudi uzimali zdravo za gotovo. Zato se u posljednje vrijeme počela voditi pojačana briga o kontroliranom ispuštanju otpadnih voda u recipijente. Osmišljeni su alternativni sustavi pročišćavanja otpadnih voda koji mogu na ekološki, zdravstveno prihvatljivi način i u velikoj mjeri riješiti problem zagađenja recipijenta. U nastavku su detaljnije obrađena tri sustava, biljni uređaji ili umjetne močvare (biljni uređaj Vinogradci), biolagune (biolaguna Ilok) i infiltracija otpadnih voda kroz zemljište pomoću sustava nebiljnih filtera.

Drinkable water is the most important resource on our planet and is also a basis of every human, animal and herbal life. The importance of preserving water and environment is becoming an even bigger priority, because the years, decades and centuries have accumulated in which people took their existence for granted. Therefore, recently has been taken an increased care of controlled wastewater discharge in recipients. Alternative systems for wastewater treatment have been invented which could largely resolve the problem of recipient pollution using ecological and sanitary acceptable methods. Three systems have been below described in detail and those are constructed wetlands (CW Vinogradci), aerated ponds (aerated pond Ilok) and non-planted filters.