Waldhuni river in Ambernath turned black on Thursday due to chemical effluents released into the water.(HT Photo)
Waldhuni river in Ambernath turned black on Thursday due to chemical effluents released into the water.(HT Photo)

The environmental tragedy in Mumbai’s hinterland

Hindustan Times | By Manoj R Nair
UPDATED ON FEB 23, 2020 11:46 PM IST

In 2017, this newspaper reported about industrial effluents being released in the Kasadi river in Taloja, an industrial town in the Mumbai Metropolitan Region (MMR).

The news was picked up by the international media, not because industrial pollution in India was a cause for concern in the West but because the story provided striking visuals of dogs with blue fur. The poor animals had been wading in the river polluted with blue runoff from dye factories, for food. A water quality test found that waste produced by the area’s factories was not treated adequately, causing severe pollution in the water body. The level of biochemical oxygen demand (BOD) — the concentration of oxygen required to sustain aquatic life — in the Kasadi was 80 milligram a litre (mg/L). Fish die when the BOD level is above 6mg/L and water is unpotable if levels are above 3mg/L.

The area is an industrial pollution hotspot. In August 2016, fishermen in the area complained that industrial effluents released into rivers without treatment were killing fish. Information obtained through a right to information (RTI) application said that the area has over 900 chemical, pharmaceutical, engineering, and food factories. Effluents released by these factories are supposed to be treated at a common effluent treatment (CET) plant before being released into natural water bodies, but the dye factory, which was found flouting environment laws, had been releasing waste directly into the river without routing it through the CET.

In May 2019, the Maharashtra Pollution Control Board (MPCB) issued notices to four cities along the Ulhas – Kalyan-Dombivli, Ambernath, Kulgaon-Badlapur, and Ulhasngar for releasing untreated industrial and domestic waste into the Ulhas, a major river in the southern part of MMR.

Punitive action has had no effect on the pollution in the area’s rivers. Last week, Waldhuni, a tributary of the Ulhas, ran orange and the MPCB issued closure notices to seven industrial units that were releasing untreated waste into the river.

Earlier this month the Supreme Court (SC) pulled up the Kalyan-Dombivli Municipal Corporation for failing to meet its commitment to stop sending untreated sewage into the Ulhas and Waldhuni. The court was hearing a petition filed by the environmental group Vanashakti. Information submitted before the court reveals that Kalyan-Dombivli treated just 30% of its daily output of 126 million litres of sewage before releasing it into the Ulhas. Other cities along the river fared only a little better.

Rivers like Ulhas and Kasadi empty into the Thane creek, an important bird and mangrove habitat that hosts migratory birds like the flamingo. The Central Pollution Control Board has said that the Ulhas and Waldhuni are among 351 polluted river stretches in the country. The rivers supply water – drawn from the relatively unpolluted upper stretches – to Mumbai suburbs like Badlapur.

The region’s hills, that affect local weather and winds, are disappearing. In January 1017, this newspaper reported that a forested hill at Mahape, which once held a 100-hectare forest, was destroyed by quarrying. Environment groups have managed to draw the attention of the Bombay high court to the illegal excavation of hills in the area.

It is not just rivers and hills in the area that are under threat. The area has vast wetlands that could disappear under construction. Raigad district has 468 sqkm of wetland area as per the National Wetland Atlas. These wetlands, which support a rich ecosystem of avian and aquatic life, are under threat as the new wetland rules exclude most sites, leaving them vulnerable to construction. The development blueprint from the area’s planning agency, the City Industrial Development Corporation Ltd (Cidco), shows that the Dronagiri node – one of the fastest developing areas in Navi Mumbai – will include at least 12 wetlands notified by the Raigad district administration. The wetlands will disappear under the Navi Mumbai Special Economic Zone. The quarries in the area are also sending debris into the Thane creek which is silting up.

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