Wastewater Reuse

Human excreta and wastewater contains a few useful materials. These are water, organic nutrients and carbon. They should be regarded as a resource. Within their natural cycles they are broken down through microorganisms and become meaningful to plants and animals, therefore sustaining natural ecosystems. While improperly disposed these substances could cause pollution, since the organic materials exert oxygen demand, and the nutrients promote algal growth in lakes, rivers and near- shore marine environments.

Human excreta and wastewater holds pathogens. Reuse of the wastes must ensure which public health is managed. Planned reuse is the key to wastewater reuse. Planning for reuse ensures which public health and protection of the environment are taken within account. Reuse of treated wastewater for irrigation of crops, for example, will required to meet

(a)    Standards for indicator pathogens, and
(b)    Plant needs for water, nitrogen and phosphorus.

Unplanned or unintentional wastewater reuse is already taking place hugely. Water is withdrawn from the river through a community, treated for water supply and distributed. After its use the water is treated, collected, and discharged to the river. This procedure is repeated several times along the river.