Almost all cities in the country face water shortage. Therefore, water conservation is of paramount importance. Apart from conserving water, it must be ensured that high grade water is used only for drinking and cooking purposes.
For other purposes, waste water can be used after purification. This will reduce the demand of potable water and save on capital costs. Technologies are available to purify the used water and make it suitable for toilet flushing, gardening and industrial use. Recycled water is currently being used in the manufacture of paper, steel, textile and air conditioning.
The Haryana Urban Development Authority (Huda) has come out with a proposal to use of treated water for toilet flushing and gardening.
The proposal, no doubt, is laudable but has potential dangers also. Any wrong plumbing either inside the building or outside can result in mixing of the drinking and recycled water causing large scale epidemics.
First, the treated water to be used for toilet flushing will have to satisfy the mandatory norms of suitability as per guidelines. As per guidelines, the effluent must undergo secondary treatment followed by filtration and disinfection. To obtain safety parameters after purification, the treatment will have to be of very high order using ultra filtration techniques.
The existing treatment plants will require upgradation and renovation so that the same could produce the expected quality. Second, a separate conveyance system for supplying this treated effluent to the houses will have to be laid sufficiently away from the drinking water pipe network
Author, a resident of DLF City (Phase 1), is former engineer-in-chief, Delhi Jal Board.