Will rubble trouble end in Bengaluru?

While the city may get a plan to dispose of construction debris, the collection system needs to be better-organised.

Bengaluru Solid Waste Management Limited, the nodal agency responsible for managing waste in Bengaluru, has floated a tender requesting bids for building and operating four construction and demolition waste management plants in the city.

Sources say four bidders have applied for this, and the tender is being finalised. If everything goes according to plan, Bengaluru will have this new construction and demolition (C&D) waste management system in place in another two years.

The Bruhat Bengaluru Mahanagara Palike reportedly aims to prevent C&D waste dumping by attaching a binding C&D management instruction to every sanctioned plan through this system.

The request for proposal accessed by DH shows that the scope of work includes collecting C&D claimed waste generated by identified generators and unclaimed C&D waste where the generator of C&D waste is difficult to identify, for instance, the C&D waste mainly found on the roadside or in other residential, non-residential and open areas within the BSWML limits.

The entire primary and secondary collection and transportation should have a vehicle tracking system equipped with GPS/ RIFD/ mobile-based tracking mechanism, weighbridges and CCTVs connected to the central control command system of BSWML.

Information, education, and communication (IEC) activities also fall under the bidder who wins. This involves creating awareness programmes among citizens, making them part of Swachh Bharat Mission-2.0 as per the guidelines, and establishing a call centre to attend the public redressal and complaint-resolving mechanism.

The bidder who wins will be responsible for lifting unclaimed waste from areas, as directed by BSWML officials. The document specifies the make of vehicles for transporting C&D waste and the companies that must buy the required machinery. It makes provision to lift waste from smaller and medium waste generators (producing less than 1 MT waste) that are not registered with BSWML. Those producing more than 1 MT and less than 20 MT must pay through an ESCROW account in BSWML.

Bulk waste generators (BWGs) producing more than 20 MT of C&D waste must send a request letter to BSWML indicating the approximate quantity generated from a newer construction, demolition or renovation. They can use the C&D plant operator’s transportation system or their own system by getting the required approvals. The required processing fee must be paid. The BWSML would be informed of the differences between the estimated waste and the waste arrived, thereby making data-based checks easy.

There will also be an “on-demand/ on-call pickup” of C&D from claimed C&D waste generators, and based on complaints. The operator must market these services. Apt safety and security measures have been specified for on-field operators.

The draft proposes four plants with 750 TPD capacity and a minimum crushing capacity of 150 tonnes/hour, which can operate for a minimum of five hours. If the received capacity exceeds the proposed capacity, the plants may need to operate for extra hours.

A period of 18 months from the date of receipt of the letter of acceptance or handing over of the site is given for the construction of the plant, whichever is later. The construction period is for establishing processing facilities, other civil infrastructures, etc. Service level benchmarks, such as hours of operation, are also established.

‘No demand for recycled products’

The RFP entrusts the bid winner with marketing the recycled products, and takes no responsibility for it. However, bulk waste generators are supposed to sign an agreement with the plant to purchase the finished recycled products. The bid winner can sell the C&D waste recycled material and value-added products to any government department or private parties in the open market.

Recycled aggregates are derived from processing construction and demolition waste, including concrete, bricks, and other masonry elements. The overall plan, adhering to the principles of circular economy, is to generate and use these in newer constructions according to the standards. However, sources say there is not enough demand for these products.

“Big builders get away by not using the prescribed amount of recycled materials. There is no monitoring system to ensure the usage,” says a seasoned source in the field of C&D waste management. Since there is no demand for the output, he says more thought needs to be put to ensure this system works.

The Indian Standards (IS) provide guidelines for using recycled aggregates in construction, primarily through IS 383:2016, Coarse and Fine Aggregate for Concrete - Specification. This promotes recycled aggregates and specifies strict quality and application-based guidelines to ensure safety and performance in residential construction. Recycled aggregates can be used in non-structural applications like pavements, roads, and pathways without significant restrictions. In structural concrete, the use is limited and must meet strict quality standards. It can be used in non-load-bearing structures, foundations for low-rise buildings, flooring, etc.

The recycled aggregates must conform to the particle size and grading requirements specified in IS 383. For structural concrete, IS 383:2016 specifies a maximum of 25% recycled coarse aggregates for general concrete structures, including residential buildings. However, fresh aggregate materials cost less than recycled items.

“In smaller residential projects, sometimes engineers argue against recycled aggregates; hence, the constructions end up using fresh materials,” says Deepak V Punam, a research scholar at the Institute for Social and Economic Change who is working on managing construction and demolition waste.

Concrete made with recycled aggregates must undergo comprehensive testing to ensure adequate strength, durability and resistance to weathering and freeze-thaw cycles. It is also tested for residential construction.

“Since the quality standards are prescribed, there is no problem using these products in non-loadbearing structures. Pavement blocks, culverts, white-topped roads, compound bricks etc. can use 50% of the recycled sand and jelly aggregate with no quality issues. It can also be used for flooring and other structures,” says Deepak.

Credit: DH Photo

‘Streamline collection system’

Sources say even government organisations such as BMRCL are not following the rules currently. A document containing a C&D waste management plan for various under-construction metro reaches shows 87,095 MT of estimated waste, of which only 27,408.89 MT was sent to processing facilities. Many complaints have been filed regarding dumping C&D waste on Airport Road and elsewhere.

Big and small private builders and contractors do not have any rules or regulations and dump the C&D waste in whatever vacant land they can find. Sources say there are examples of using unprocessed C&D waste on the same land, which also led to the collapse of the structures.

“No one stops the construction for the lack of space to dump the C&D waste. There is no accountability,” the source points out. BBMP hopes to fix this issue by linking the C&D waste management plan to the plan sanction.

Deepak says a hub-and-spoke collection system, with a collection centre in every 5 km radius, is necessary to reduce transportation costs and avoid contributing to traffic congestion. He adds that Delhi uses such a system, which helps streamline the collection.

The RFP floated by the BWSML does not talk of such a system. BWSML officials were unavailable for comment.