Mayor Bonthu Ram Mohan vouches that the residents of about 30 villages and colonies surrounding the infamous Jawahar Nagar dump yard can now breathe easy, literally.
Eighty three per cent of soil capping is complete for the legacy garbage dump at the 135-acre dump yard and the work up to 95% will be complete in the next 15 days, say the officials from the Ramky Enviro Engineers, the agency managing the dump yard since 2012.
In another significant move, a channel was dug for drainage of rainwater circumventing the Malkaram Lake nearby, to ensure the leachate does not enter into other water bodies when the lake overflows during rains.
Malkaram Lake was so highly polluted by leachate seeping from the legacy dump that the water turned black and the plant life in the lake was near-dead. During rains, the situation worsens as the overflowing lake pours its pollution into other water bodies in its network, including Dammaiguda Cheurvu and Pedda Cheruvu.
Leachate seepage occurs when the slime oozing out of the legacy dump is mixed with rainwater and flows out into lakes and other water bodies.
However, the leachate already collected in small ponds around the dump yard still needs to be treated before it is let into Musi River.
Of the total 7.5 million litres of leachate collected in them, only 2.4 lakh litres have been treated so far, by the two treatment plants each of two kilo litre capacity per day.
It is hoped that the ponds will not receive fresh rainwater which would increase the volume of leachate.
12 m tonnes of waste
The legacy dump, referring to the 70-80 metres high hillock of 12 million tonnes of waste deposited here since 2001, will be completely covered in six layers by April next year, Mr. Ram Mohan said, during a media tour of the dump site on Monday.
Experts from the Hyderabad Integrated Municipal Solid Waste Limited, a subsidiary of Ramky, explained that the soil cover 300 millimetres in thickness will be followed by a non-permeable geosynthetic clay liner, a flexible membrane layer of HDPE, and a geo-drainage layer to provide storm water channels on the mound. Final topping will be of restoration soil with 450 mm thickness, on which vegetation will be grown.
Gas vents will be provided in the dump to collect and fire Methane and such other gases produced within.
Of the 135 acres of dump, so far, 112 acres have been covered in initial layer of soil. A total of 5.5 lakh tonnes of soil has been excavated from Kapra Lake and Nalla Cheruvu of Uppal for this purpose. The final layer will require 6.5 lakh more tonnes.
Mr. Ram Mohan claimed that the capping of this scale is the first time in the country, though smaller capping work had been done earlier in Mumbai and Agra.
Reclamation of the dump site started from December 2016, and gathered speed only recently after vociferous public agitations.