To fight the scarcity of water people are now finding ways to recycle and reuse waste water for domestic purposes other than drinking. Doing this reduces the stress on the requirement for fresh water.

The onsite system of waste water treatment is gaining popularity. Onsite system is a natural method or mechanical device that is used to collect, treat and discharge or reclaim waste water from an individual residential area without the use of community wide sewers or a centralized treatment facility. A septic tank and a drain field are the components of a conventional onsite system. The alternative onsite systems include at-grade systems, mound systems, media filters, small aerobic units and pressure distribution systems.

A waste water collection and treatment system that serves two or more dwellings, but less than an entire community is called a cluster system. The waste water from several homes is pretreated by individual septic tanks or aerobic units before it is transported through low cost, alternative sewers to a treatment unit which is relatively small compared to centralized systems.

A decentralized system uses an onsite or cluster wastewater system to treat and dispose of relatively small volumes of waste water which originates from individual or groups of dwellings and businesses that are located close together. Onsite and cluster system can be used in combination to reap good results.

Each builder in Kerala has under consideration these waste water systems for the projects so as to reduce the huge water demand and use the recycled water for purposes that can comprise on the purity of water.