Only one-third of India's wastewater is treated, over 70% flows to environment: CSE

New Delhi: Less than one-third of India’s urban wastewater and sewage are treated, leaving over 70 per cent of untreated wastewater flowing into rivers, lakes and land, the Centre for Science and Environment says in a new report.

The report that looks at gap areas in the sewage treatment system found that only 28 per cent of the total urban sewage is being treated, implying 72 per cent of the wastewater remains untreated and is disposed of contaminating the environment.

Moreover, it notes that 20 per cent of groundwater blocks are in critical condition or overexploited; 55 per cent of the households have either open or no drains and 91 per cent of 302 river stretches are polluted.

The report comes at a time when India’s per capita availability has been witnessing a steady decline as it currently stands at 1,545 cubic metre from the highs of 5,200 cubic metres in 1950s and 2,309 cubic metres in 1990s.

This makes India one of the water-stressed countries with indications of the situation worsening in the years to come.

“India faces significant water scarcity challenges due to rapid urbanisation, industrial growth, population expansion – and most importantly -- climate change. Wastewater reuse can be a key part of the strategy to address these concerns and promote water circularity and sustainability,” said Sunita Narain, CSE director general.

The Jal Shakti Ministry has mandated that cities must recycle and reuse at least 20 per cent of the water they consume. The situation on the ground, however, varies from state to state as the CSE report notes while looking at eight states, including Karnataka.

In Karnataka, only 43 per cent of the total sewage is treated for reuse in the industrial sector, lake recharge, irrigation and horticulture. The major reuse (67 per cent) is for lake rejuvenation, followed by irrigation and industrial purposes.

In Bengaluru, over 75 per cent of total wastewater is treated and most of the reuse happens for lake revival with an objective of recharging shallow aquifers which can be ultimately used for agriculture or domestic water supply.

“There is a need for developing a groundwater monitoring unit in Bangalore Water Supply and Sewerage Board to measure quantity and quality of groundwater near the lake vicinity to understand the impact of lake revival and recharge,” the report said.

“Also, there should be a dedicated wastewater management cell to oversee and supervise all the planning and execution of the reuse of treated wastewater.”

The report points out that the gap in total sewage water generated and its treatment is the highest in Uttar Pradesh, followed by Maharashtra, Karnataka, Rajasthan, Tamil Nadu, Delhi and Haryana.

But cities like Bengaluru, Chennai and Nagpur have taken initiatives to reuse wastewater after treatment. However, such activities are limited and need to be expanded.

“Using and disposing treated water, without harnessing its potential, means we are losing out on utilising an important resource. The challenge is to scale up,” said Rajiv Mital, CEO, National Mission for Clean Ganga.