Silt from drains adding to burden at Delhi’s landfills

New Delhi's pre-monsoon desilting programme has led to more than 600 tonnes of silt being deposited on the city's landfill sites every day, which is slowing down the process to flatten them. The Delhi government has directed the Municipal Corporation of Delhi to explore using the treatment facilities of the Delhi Jal Board for silt treatment. The civic body plans to remove 103,111 tonnes of silt by 15 June, with most ending up on the Bhalswa and Okhla landfill sites.

New Delhi: With the pre-monsoon desilting of the drainage network of the city in full swing, more than 600 tonnes of the silt is ending up every day on the already oversaturated landfill sites slowing down the process to flatten them. Municipal Corporation of Delhi (MCD) has been directed by the Delhi government to explore utilisation of the treatment facilities of Delhi Jal Board (DJB) — the water agency of the city which deals with the silt from sewage — for silt treatment. Under its annual action plan for pre-monsoon preparation, the municipal corporation plans to remove 103,111 tonnes of silt till June 15 this year most of which ends up on the Bhalswa and Okhla landfill site.

A view of debris dumped after cleaning the sewage near Vinod Nagar, in New Delhi on Monday. (Sanjeev Verma/HT)

A senior MCD official said that with the drain clean-up gathering pace, the amount of silt being deposited on landfills is likely to increase in coming days. “A review meeting was held with the chief minister and urban development department during which the directions were issued to prepare a plan so that silt is not dumped at the SLF (secured landfill facility) else the mountains of garbage will not be removed. The government has directed that for the disposal of this silt, an agreement with DJB be explored as DJB has capacity of silt disposal,” official added. HT has seen a copy of the directions.

Bio-mining process and remediation process separates various components of legacy waste such as plastic, paper, cloth, sand, bricks etc. by passing them through a trommel machine which acts as cylindrical rotating sieves. Dumping more silt and fresh waste reversed the progress and slows down the net gains but there are no alternatives available with the civic body, an MCD official admitted.

While the pre-monsoon desilting programme of city’s drainage network is an annual practice, the renewed focus on the project to flatten the landfill sites by next year has brought the silt dumping on landfill sites under the scanner. Clearing the “garbage mountains of Delhi” was one of the ten promises made by the AAP in the run-up to the municipal elections held last year. Delhi chief minister Arvind Kejriwal had visited the landfill sites in March whereby he had announced the new expedited deadlines for cleaning the landfill sites. According to the deadlines fixed by the government, the Okhla site needs to be cleared by December this year, Bhalswa by March and Ghazipur by December next year.

A DJB official said that discussions have been held with the corporation and formal memorandum of understanding (MoU) will be signed in this regard. “Delhi Jal Board has surplus capacity in its bio-digesters. DJB already treats silt from sewage. The silt from drains will need pretreatment which will depend on the organic content in the soil. As the final product of this process, DJB plants can produce paver tiles with this inert material. We have also experimented with the inert material from Bhalswa at the Kondli silt treatment plant to create tiles and paver blocks. The two organisations can work together to solve this problem,” the official added.

An MCD official, echoing the DJB official, said that the civic body is exploring possibility of using DJB’s facilities for processing of wet waste and the silt shall be utilized for making bricks at the construction and demolition plant. “We will carry out a pilot with DJB and if it successful the project can be taken up,” the official said.

Bharati Chaturvedi, environmentalist and founder of Chintan Environmental Research and Action Group, which specialises in waste management, said that over time the level of roads have got higher and higher and every piece of dust by design ends up in drains. “We need to reconsider how we build roads and drains so that drains don’t end up being silt deposit traps. We need to test this silt for heavy metals and toxic compounds. It is okay for inert silt to be dumped but the accompanying plastic waste should not be in it. Silt is reasonably inert and can be dumped on landfills but we must test it first for toxicity.” Chaturvedi said.