Delhi's Water Future: Wastewater Reimagined

Delhi is embarking on a significant shift in its water management strategy by prioritizing the reuse of treated wastewater.

The Delhi Jal Board (DJB) plans to implement a dual-pipeline system in upcoming residential projects. This system will supply potable water for drinking and bathing, while extensively treated wastewater will be utilized for non-potable purposes such as flushing toilets and washing clothes and utensils.

A senior DJB official highlighted the plan to establish tertiary water treatment units to further purify water from Sewage Treatment Plants (STPs). This enhanced water will meet inland water quality standards, making it suitable for household tasks. The first pilot project for this initiative will be launched in Narela.

Delhi faces a daily water deficit of approximately 250 million gallons (mgd), with demand reaching around 1,250 mgd. Recognizing that additional freshwater from dam projects is not expected until 2032-33, the DJB is focusing on reducing reliance on potable water for activities that do not require it.

The proposed system involves a second pipeline carrying treated water with strict quality standards, targeting BOD and total suspended solids (TSS) around 3 mg/L. While not for drinking, this improved quality will make it viable for various household applications currently consuming freshwater.

To support this strategy, the DJB is introducing the Reclaimed Water Policy, 2026. This policy aims to establish treated sewage as a dependable resource for non-potable needs. Furthermore, charges for water supply to farmhouses are likely to increase to encourage the adoption of treated wastewater and decrease groundwater dependency.

Currently, Delhi treats about 750 mgd of sewage, with approximately 483 mgd available for reuse after environmental flows. However, only about 120 MGD is currently being reused, primarily for irrigation. This leaves a substantial surplus of nearly 363 mgd of treated water with potential for broader application, including construction, horticulture, industrial cooling, and more.