Hyderabad: As Hydraa ramps up efforts to reclaim and rejuvenate Hyderabad’s lakes from encroachments, the city’s green brigade highlights significant challenges facing this mission: inefficiency of Sewage Treatment Plants (STPs) and the unchecked diversion of untreated sewage. While the Hyderabad Metropolitan Water Supply and Sewerage Board’s (HMWSSB) data claims that 168 STPs around 70 lakes — out of 185 notified — are functional, a recent visit by TOI to some water bodies painted a different picture.
It not only found many of these STPs dysfunctional but also saw some of these lakes inundated with sewage. Locals and environmentalists said it was the result of STPs either not working or having limited capacity.
The Hussainsagar Lake, for instance, is dependent on two STPs — one with 20 megalitres per day (MLD) capacity at the Kukatpally channel and another with 30 MLD capacity at Picket Nala. Yet, the areas around these STPs are found choked with sewage and hyacinth.
“The STPs are outdated and have been dysfunctional for a long time,” alleged Lubna Sarwath, an environmental activist. According to her, industrial effluents from the Kukatpally channel are a primary source of pollution for the lake causing frothing near Necklace Road, the Marriott Hotel, and the Greater Hyderabad Municipal Corporation (GHMC) office. Though a new STP of five MLD capacity that was built at a cost of Rs 8.2 crore at Minister Road is functional, its limited capacity barely helps filter the water.
Also, plans for two additional STPs of eight MLD and six MLD respectively have been abandoned after HMWSSB officials claimed they were unnecessary, as sewage was diverted to the Amberpet STP, the largest in the city with the capacity to filter 340 MLD of waste.
According to multiple reports, Hussainsagar generates over 120 MLD of waste. The existing STPs, therefore, can only filter a fraction of this waste.
Incidentally, GHMC, which is responsible for maintenance of Hussainsagar STPs, admit to the shortcomings. “Only one STP near Picket Nala is working which treats one sewage line. There are four sewage lines, the major one being the Kukatpally channel from where most of the pollutants enter the lake. While we are trying to see if we can divert the sewage flow to only one side of the lake, through the intersection and diversion system, there is no concrete plan that we have drawn up yet,” said the assistant executive engineer from the lake division of GHMC.
At Durgam Cheruvu, environmentalists allege that the two STPs — of 7.5 MLD and 5 MLD capacity — are far from enough to keep the lake clean. According to them, close to 50 MLD of untreated sewage still flows into the water body every day. “In fact, the STPs are often inundated with rainwater and mud, rendering them ineffective,” said S Reddy Nakka, an environmentalist and resident of the area. “Even with the windows closed, the foul smell is inescapable. I used to take walks every day but stopped last month because of the stench,” said 61-year-old Sri Shobha, who lives near Durgam Cheruvu.
The stink was pronounced even when TOI visited the water body recently.
In the city’s southern region, Mir Alam Tank has two STPs—a 5 MLD plant near the midfield arena and a 10 MLD plant near the GHMC office. However, TOI found both defunct during its field visit. Social activist SQ Masood pointed out that while one STP stopped functioning years ago, the other never took off due to “technical issues”. An incomplete box drain and diversion system has further compounded the problem here. “Effluents from Noor Mohammad Kunta tank, heavily polluted by industries in the Kattedan area flow into Mir Alam Tank carrying hazardous waste from industrial units and sewage from nearby neighbourhoods,” said activist Mohd Imdad.
When asked about it, a HMWSSB official passed the buck onto GHMC. He said: “Our job ends with installing them. The maintenance lies either with the GHMC or HMDA. The lakes which do not have STPs, their sewage is diverted to a nearby lake which has a STP. But due to excessive dumping, these channels often get blocked.”
The ideal practices apart from STPs to keep the lakes clean include Floating Treatment Wetlands to enhance water quality, manage watershed nutrients, and treat wastewater and industrial contaminants. Moreover, aerators should also be introduced to facilitate aerobic biodegradation of organic materials in wastewater and enhance the water quality. There is also a need for efficient stormwater treatment, functional STPs near outflow channels, and diffusers. — Madhulika Chaudhari, an environmentalist who has revived lakes in Hyderabad.
We are going to collaborate with various departments including HMWSSB and PCB to ensure the functionality of the STPs. Using remote sensing technology, we will identify the sewage inlets and divert the sewage. The proposal to restore 12 lakes is in the pipeline and we will start restoring them soon. — A V Ranganath, Hydraa commissioner.
