If not overloaded, bacteria in the environment will consume organic contaminants, although this will reduce the levels of oxygen in the water and may significantly change the overall ecology of the receiving water.
== Obdelava v sprejemnem okolju ==Veliko procesov v čistilnih napravah je zasnovano tako, da posnema naravne procese obdelave, ki se pojavljajo v okolju,včasih je to v okolju naravno vodno telo ali tla.