soon this is what the looking swell looked like. tariff occasion system is based on maintaining an active ecosystem sewage accumulates in the first tank. sunlight enters the water and provides the energy necessary for pollution consuming micro algae to grow. these photosynthesize and produce oxygen essential to the development of billions of aerobic bacteria that will more completely digest the waste. the water undergoes purification for several weeks in the first place. in the second and third tanks plants refine the water quality so that it can be used for field irrigation. the reuse