KARNATAKA

Plastic, chemical effluents continue to choke Vrishabhavati

(Clockwise from top) Garbage dumped in the Vrishabhavati at Kumbalgod and illegal plastic and waste segregation units that have come up on the riverbank at Kambipura.K. Murali KumarK. Murali Kumar

(Clockwise from top) Garbage dumped in the Vrishabhavati at Kumbalgod and illegal plastic and waste segregation units that have come up on the riverbank at Kambipura.K. Murali KumarK. Murali Kumar  

BWSSB authorities say waste, including chemicals, is being surreptitiously dumped into the river at night during weekends

The new Namma Metro line runs along its bank in some parts and on the other side, apartment complexes tower over it as the Vrishabhavati snakes its way through the west of the city with mounds of garbage floating on its dark water.

The story of the Vrishabhavati has been one of deterioration that is spinning out of control, so much so that it is often referred to as Kengeri mori (drain) — a far cry from being a drinking water source a few decades ago. Today, pollutants from industries, raw sewage, plastic waste, and just about any discard that is too inconvenient to be thrown anywhere else finds its way into the Vrishabhavati, the only river that originates in Bengaluru.

According to water conservationist S. Vishwanath, the river is believed to originate near the Bull Temple in Basavanagudi, and gets its name from ‘Vrushabha’ (bull). In the 1930s, Sir M. Visvesvaraya built the Byramangala dam. It flows through Guddadahalli, Bapujinagar, Rajarajeshwarinagar, and Kengeri, among other neighbourhoods, gathering pollutants along the way before it joins the Arkavati at Kudlu.

Though many point to the establishment of the Peenya Industrial Area as the factor that led to polluting the river, Mr. Vishwanath said it had begun with the advent of the Cauvery water supply, which increased sewage load on the river. Industrial effluents got added to domestic sewage after Peenya Industrial Area came into being. “Vrishabhavati and Bellandur lake are on the same plane. Both will be revived only when we put a significant amount of investment in our sewerage network and in our industrial effluent collection and treatment. At the current investment level, it is unlikely that these two will be cleaned up. It could take close to 25 years for them to be revived,” he said.

But he said that globally this has been the position that growing economies tend to spoil their water and it is only after you reach a certain stage of development that you have the money to invest in cleaning it — known as the ‘Kuznets curve’.

Unchecked dumping

Plastic and waste segregation units appear to be one of the newer threats to the river. At many points, mounds of plastic waste can be found washed ashore the riverbank, one of them is close to the Kumbalgodu police station.

Near Kambipura, waste segregation units, which local residents allege are illegal, continue to dump plastic and burn metals and plastic. “In some parts, these units have closed in on the boundary of the river by dumping mud,” said residents.

Residents alleged that waste segregation units multiplied recently. “Initially, there was only one unit which the authorities shut down after we took it up with them. Now, there are multiple units along the bank,” said a resident.

In recent times, there have been multiple instances of trucks surreptitiously dumping waste, including chemical waste, into the river — a fact that even the Bangalore Water Supply and Sewerage Board (BWSSB) acknowledges. “There is concern over some industries dumping chemical effluents into our manholes at night during the weekends, though our lines are only meant to manage sewage. There is a Supreme Court order that bigger industries need to have their own ETPs (effluent treatment plants), but many are not following it,” Tushar Girinath, BWSSB chairman, told The Hindu .

Contamination

In 2016, researchers of Ashoka Trust for the Environment and Ecology confirmed this through their findings from a year-long study involving monthly 24-hour sampling, according to which there was illegal discharge from industries at night. They collected water samples from three villages downstream of Byramangala tank and their analysis revealed contamination, particularly of heavy metals such as nickel, copper, chromium, lead, and manganese, which had seeped into the soil and groundwater and were also found in milk and vegetables.

The researchers pointed out how it was not only the local population at risk, but also those who ultimately consume the food.

STP network

The BWSSB promises that work is on to improve its STP network. An ETP is expected to come up at Peenya from the Karnataka State Pollution Control Board (KSPCB), though the capacity has been downscaled.

The BWSSB chairman said Vrishabhavati was expected to get 525 to 540 MLD flow of treated water. “The STP at Mylasandra is of 75 MLD, at Kengeri 60 MLD, at Vrishabhavati the 180-MLD STP is under rehabilitation and we are constructing a new one of 150-MLD capacity — both of which will be completed by July. There are also the two-year-old 20- MLD plant and 40-MLD new plant at Doddabele,” explained Mr. Girinath.

However, with the flow from the 110 villages also joining the Vrishabhavati, there could be a shortfall in treatment. “We are adopting a flow analysis. In Kengeri, 20 MLD excess capacity is ready for operationalising whenever flow picks up,” he said.

But it is the effluents that has the water board worried, as they destroy bacteria, which in turn destroy nutrients, according to Mr. Girinath. “In Kengeri, for instance, we couldn’t operationalise the full 60 MLD as all sorts of things were coming in. Four pumps went bad. Now, we are thinking of more coarse pumps,” he added.

The BWSSB is also contemplating surveillance, mainly at night, along with the police and the KSPCB, to keep a check on the menace.

(First of a two-part series)

There is a Supreme Court order that bigger industries need to have their own effluent treatment plants, but many are not following it.

Tushar Girinath,BWSSB chairman

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