Today, the problem of construction and demolition (C&D) waste is becoming too hard to handle. It´s time for city corporations to take immediate action, developers and contractors to get more responsible, and a legal mandate to be imposed to manage, recycle and reuse this waste.
In a growing city, infrastructure and housing projects generate large quantities of construction & demolition (C&D) waste. Take the city of Delhi; reports point out that it generates 4,000-5,000 tonne per day of C&D waste. This along with municipal waste gets accumulated in an unauthorised manner at various dumping sites, such as low lying and public land or along roads, ridge areas (the city´s green lung) or riverbanks. Dust from construction activities also adds to particulate matter (PM) levels in the air. Combined with road dust, C&D waste contributes to over 30 per cent of Delhi´s alarming air pollution levels, according to an IIT-Kanpur study. Delhi is not alone - every city is getting choked by huge levels of C&D waste. Unfortunately, the amount generated in many of these cities remains unknown; in some instances, to city corporations as well.
According to a report by the Central Pollution Control Board, over 25 per cent of the total solid waste generated in India comes from construction waste alone. But C&D waste is grossly underestimated. Although built-up area has increased dramatically, official estimates of C&D waste in India have not changed for over a decade. For instance, in 2000, the Ministry of Urban Development (MoUD) estimated 10-12 million tonne; in 2001, Technology Information, Forecasting and Assessment Council (TIFAC), Department of Science and Technology, estimated 12-15 million tonne; in 2010, Ministry of Environment and Forest, estimated 10-12 million tonne; and while MoUD had no estimates in 2014, it estimated 10-12 million tonne again in 2015.
For its part, the Centre of Science and Environment (CSE) has estimated C&D waste based on TIFAC factors for C&D waste and Mckinsey estimates for trends in built-up area in India. Avikal Somvanshi, Senior Research Associate, Sustainable Buildings and Habitat Programme, CSE, shares, ¨In 2013, Indian buildings generated over 530 million tone, 44 times more than existing official estimates.¨ This is without taking into account C&D waste from infrastructure projects like roads, dams, flyovers and bridges.
In another approximation, Dr Soumen Maity, Team Leader-Technology, Development Alternatives, cites, ¨The estimated C&D waste generated in India is 716 million tonne per annum.¨ This is based on a statistical analysis of primary data obtained from 10 cities - a nationwide initiative by Development Alternatives and GIZ. These cities include Delhi, Mumbai, Kolkata, Chennai, Bengaluru, Ahmedabad, Coimbatore, Bhopal, Jaipur and Patna (see table below).
So what are most cities doing with the generated C&D waste?
¨Most cities are dumping the C&D waste at undesignated sites, which includes riverbeds and the road side,¨ responds Dr Maity. ¨Instead, the waste should be segregated at site and sent to processing facilities. It has the potential to be reused as aggregates in concrete, as M-sand, production of paver blocks, curb stones and other products.¨
Also, while materials like wood, metal, steel rods, unbroken ceramics and bricks can be reused, concrete debris, mortar and broken bricks can be recycled. (see Different Types of C&D Waste on page 50). Also, crushed C&D waste can be used as sub-base layer for roads.
Considering India´s strong informal sector, when a building is set up, many people stand outside to take bricks and similar materials that can be reused to the secondary market. In fact, Somvanshi estimates that almost 30-40 per cent of demolition waste is readily reclaimed and reused by the informal sector. However, materials such as concrete and finer waste cannot be directly reused, and needs to be recycled. Recycled waste can be used as a substitute for natural sand and aggregate in concrete mix. However, as Dr Maity points out, ¨The challenges may lie in waste procurement and making the product marketable to be taken up by entrepreneurs as a viable business.¨
Making it right
In an effort to set things right, MoUD has asked all states to look into the possibility of installing C&D waste recycling facilities in cites with a population above 10 lakh. ¨The Delhi Government has issued an advisory to all departments to modify their tender conditions to use minimum 10 per cent of recycled C&D waste products in their construction works,¨ says Mahesh Babu, Managing Director, IL&FS Environmental Infrastructure and Services Ltd (IEISL). IEISL along with North Delhi Municipal Corporation, has initiated a unique recycling plant at Burari, Jahangirpuri (read case study on page 52). And as Babu tells us, the East Delhi Municipal Corporation (EDMC), PWD and DMRC are replicating the C&D waste recycling model in other parts of Delhi. IEISL is mandated to manage 3,650 tonne per day of C&D waste in the city. Similarly, the firm has implemented the second C&D waste recycling facility at Shastri Park in East Delhi. The facility will get mixed C&D waste from 15 designated sites of East Delhi. Further, PWD has mandated IESIL to implement two facilities each of 500 tonne per day at Libaspur and Tikri whereas a 150-tonne-per-day facility will be established in Rohini, a DMRC mandate. What´s more, the company has also received an LoI from the Municipal Corporation of Gurgaon to implement a 300-tonne-per-day C&D waste recycling facility.
Going forward, other cities, including Jaipur, Bengaluru and Pune, are planning similar facilities, and some are in the process of floating tenders to rope in private players (see interviews with municipal corporations). ¨We are in the process of finding a solution to the problem of C&D waste,¨ says Rajeev Jadhav, Commissioner, Pimpri Chinchwad Municipal Corporation. ¨Pune Municipal Corporation is in the process of floating a tender, and we would like to know the exact mechanism.¨ At present, the city has huge stone quarries and C&D waste is diverted to fill some of these. ¨Also, whenever there is a need for leveling on sites, we divert such waste,¨ he adds. Meanwhile, Thane Municipal Commissioner Sanjeev Jaiswal has worked out a plan to convert construction debris into paver blocks and tiles.
At the central level, the Cabinet recently approved an MoU between Norway-based SINTEF and Central Public Works Department for cooperation in scientific research in the field of waste recycling. Mahesh Mudda, Managing Director & CEO, New Consolidated Construction Co Ltd and Honorary General Secretary, Builders´ Association of India, says, ¨SINTEF is a massive organisation that will add greater value in terms of putting in procedures and generating awareness on how best to utilise waste.¨ What´s more, MoUD recently decided to allow the use of C&D waste to the extent of 20 per cent of coarse and fine aggregates.
Are the generators reusing?
While maximum C&D waste is generated from demolition projects, contractors and builders must be responsible enough to manage the fallout.
¨Reducing waste at source is our primary concern,¨ says Rezwan Razack, Joint Managing Director, Prestige Group. ¨We ensure that hard flooring is precut in the factory itself to avoid waste. And whatever little is wasted is used within the site. Some materials are also used in non-public areas. So the waste is powdered, crushed and used for roads. Also, waste in terms of damaged and broken pieces is segregated and used in areas such as rooftops, tops of water tanks, etc.¨
Ajay Nahar, Chairman and Managing Director, Nahar Projects, draws up a list of materials that can be generated during construction activities:
¨Material wastage include cement bags, sand gravel, aggregates, spilled or damaged concrete, rebar waste, bricks or blocks, tiles, wood frames, wooden shuttering, marble or granite, natural stones, aluminium or MS sections, glass, PVC rubber, UPVC/PVC/GI/stoneware/CI pipes, gypsum or POP, paint putty, wires or cables, conduits, etc.¨ However, this waste can be reduced with some strategies or precautions.
According to Nahar, these include procuring material as per actual need; making concrete mix as per actual quantity required; mixing paints as per actual quantity required; reusing waste to fill up low land level at non-public areas; using debris to fill up reclamation area, and sending steel waste to the rolling mill for rerolling (scrap).
Meanwhile Mudda bemoans, ¨While big tiles, crude, metal, etc, are reused to some extent, almost 50 per cent of waste material such as concrete, masonry and others is not being recycled and instead dumped in city outskirts.¨ At the same time, he points to some developed countries internationally that recycle the entire building (see Global Best Practices on page 54-55).
It begs the question: Can green certification and rating systems such as TERI-GRIHA contribute in this regard? Mili Majumdar, Senior Director, Sustainable Habitat Division, TERI, responds, ¨As per the rating criteria, we go to the site and see how materials are handled, whether they are recycled, and how construction waste is being disposed.¨ She adds, though, that this must be industry-driven.
¨If people are not willing to recycle the generated waste and use products in construction, there is less one can do about it.¨
On behalf of the Builders´ Association of India, Mudda adds, ¨Most of our centres are involved in spreading the message of Swacch Bharat Abhiyan. So when we speak of Clean India, it is also about recycling material and managing construction waste in a more systematic manner. We have been trying to spread awareness among architects and developers.¨
Making it a mandate
When CW connected with about six municipal corporations, almost all agreed that there were no definite laws with regard to C&D waste. However, things are beginning to change. As Somvanshi says, ¨Municipal Solid Waste (Management and Handling) Rules 2015 has introduced a separate chapter on C&D waste.¨ To this, Dr Maity adds, ¨We are working with MoEF in formulating the guidelines. While this is in the draft stage, we have suggested they don´t merely focus on the need to throw waste out but term ´waste´ as a ´resource´. The moment this transformation takes place, the overall outlook will change.¨
Commenting on the standards for recycled products, Somvanshi adds, ¨The BIS amending IS: 383 will allow use of non-natural materials to be used for construction. The standard will now permit part substitution of natural aggregate in concrete mix with recycled aggregate made from C&D waste and slag.¨ Dr Maity, who is part of the committee working towards the formation of the code, says, ¨While making a new code can take ages, we are trying to introduce small changes that can be done within a year or two.¨
Despite the lack of separate laws for C&D waste at present, there are separate laws for segregation. When C&D waste is dumped, it is done in an un-segregated manner. So, if a law is made stating that municipal authorities will collect segregated waste, the entire problem of disposing and reusing can be solved.
Dr Amiya Kumar Sahu, Founder & President, National Solid Waste Association of India (NSWAI), says, ¨It is the duty of the State Pollution Board to check and the municipality to ensure that construction waste is not collected or dumped in municipal solid waste. At present, in the city of Mumbai, you will not find construction waste with municipal waste. It is collected separately and goes for recycling; very few people recover sand from it.¨
City corporations, developers and contractors can come together to ensure that construction and demolition waste is managed to its best potential. Here are some industry suggestions:
Indeed, these suggestions point to viable ways to deal with the rising quantity of C&D waste in our cities. But there´s no time to dither - we must act now.
Civic Talk: Delhi
¨The amount of waste generated in Delhi is around 2,000 metric tonne per day.¨
Yogendra Singh Mann, Director-Press Information, North and East, Delhi Municipal Corporation, gives an update on the city´s initiative to manage C&D waste.
The corporations are not land-owning agencies and have to depend on the Delhi Development Authority or the Delhi Government for land. For forthcoming plants as well, we are looking to engage other private players who can offer good technology.
Towards Swachh Dilli and Swachh Bharat!
India´s first large-scale operational construction and development (C&D) recycling facility in Burari is an initiative by North Delhi Municipal Corporation (NMC) with IL&FS Environment Infrastructure & Services Ltd (IEISL) on a PPP framework. The facility gets mixed C&D waste from 47 designated points in three zones of NMC. Mahesh Babu, Managing Director, IEISL, takes us through the details of the recycling plant.
The wet process adopted in the plant controls noise and dust. The plant is compliant with MSW rules and was originally set up to manage 500 tonne per day. The Delhi Pollution Control Committee then enhanced the project´s capacity to 2,000 tonne per day. And the facility has already processed close to 2 million tonne of waste.
Around 30 designated points have been notified by NMC where small generators of C&D waste can dump their waste. Depending upon generation, wastes from such sites are periodically collected by IL&FS. These 30 points cover 50 per cent of the area of NMC. Also, bulk generators of C&D waste come from big builders and government agencies, who bring their C&D waste to the processing facility. Further, waste is transported with skips and tipper trucks. Loaded trucks are covered with tarpaulin to prevent any spillage or dust pollution during transportation. According to a circular issued by the then unified corporation, bulk generators pay Rs 205 per tonne of C&D waste as processing fee for getting their waste processed at the Burari facility.
Mixed C&D waste?manual segregation?mechanical resizing?screening and washing?resized aggregate (60-20 mm, 20-10 mm, 10-3 mm, 3 mm-75 micron). Wet processing consists of grizzly, vibro screens, evo wash, thickener that is capable of segregating sand from mixed C&D waste. The wet processing system is designed for feed capacity of 60 tonne per hour and sand washing capacity of 40 tonne per hour. Treated sewage water is used for processing. The plant is further divided into three segments of segregation, crushing or washing and product manufacturing.
Segregation includes manual and mechanical segregation of concrete blocks from the mixed C&D waste. Large concrete blocks are separated from the received waste. Recyclables like red bricks are recovered. Odd-sized concrete waste like test piles, etc, are broken to small pieces, before being fed in the processing unit. The remaining soil concrete and brick waste is sent to the wet processing section and the big concrete blocks for dry processing.
In crushing and washing, large blocks are crushed and resized for further processing. Aggregates of various sizes of 20 mm to 10 mm, 10 mm to 3 mm, and 3 mm to 75 microns are obtained. Crushing is done using impact crushers and jaw crushers. Using a hydro-cyclone, silt and sand are separated from mixed C&D waste. ò In product manufacturing, each material is used in a definite ratio, and end products are made. Concrete blocks are crushed to make RMC and precast products like tiles and paver blocks. The brick sub base is used to make concrete cement blocks. Apart from this, the aggregate is used directly as construction material and sub-base for roads. Recovered sand has been positioned as 'mortar sand' and is used for brick laying during construction.
Two categories of clean aggregates are produced from the system:
Recycled concrete aggregates consist of aggregates produced by crushing concrete separated from C&D waste. These are used for making value-added products like pavement block, kerb stone, drain covers and other non-load-bearing precast products.
Mixed concrete and brick base are converted into recycled aggregates for making mortar sand, concrete blocks and granular sub-base.
The Burari plant is able to recover and recycle about 95 per cent of incoming C&D waste. What´s more, the facility has helped save over 25 acre valued at over Rs 250 crore.
Global Best Practices
Did you know that the Olympic Stadium in London used 30 per cent recycled concrete in its construction? Here are some more interesting facts. In Australia, Nalawala Hall, Fairfield City Council´s sustainability hub, incorporates the world´s first concrete load-bearing foundation slab, which is 95 per cent recycled. In Scotland, about 63 per cent was recycled in 2000. Denmark and Netherlands have an aggressive strategy to reuse construction and demolition (C&D) waste. And the Netherlands has found that 80 per cent of its C&D waste is bricks and concrete that can be recycled to minimise pressure on land. The Centre for Science and Environment (CSE) and Development Alternatives share a few more case studies of international best practices in managing and recycling C&D waste. Inspiration, no doubt, for India...
SOUTH KOREA: This nation has one of the most extensive and oldest recycling policies for C&D waste. C&D waste management is part of its Low Carbon Green Growth strategy. The country has a law, Acceleration of C&D Waste Reuse/Recycling 2005, which provides for step-by-step demolition and utilisation of recycled aggregates. It has adopted separate building codes for recycled asphalt concrete aggregates, recycled concrete aggregates, and road pavements. The Architectural Institute of Korea Standard Building Construction Specifications recommends increased use of recycled C&D material. The effective recycling rate in Korea is 36 per cent with a target of increasing this to 45 per cent by 2016.
SINGAPORE: This is yet another land-constrained country that recycles 98 per cent of its C&D waste. HONG KONG: With serious land constraints, it cannot afford landfills. Thus, it has stringent controls over C&D waste and imposes a waste charge on developers. The system has lowered the quantity of C&D waste needing disposal at landfill by 60 per cent. Also, rates have been structured to incentivise on-site recycling and reuse; 100 per cent waste utilisation is charged at HK$ 27 per tonne while over 50 per cent waste needing landfill disposal is charged at HK$ 125 per tonne. The revenue generated is used to maintain and subsidise C&D waste recycling centres. Tax concession is also offered to these centres. These measures have generated efficient construction practices that minimise the generation of construction debris. Instead of demolishing structures, they are dismantled systematically.
THE EUROPEAN UNION: The EU has set clear rules regarding the use of recycled material in buildings. EU 2004 regulations in the form of European Standards for Aggregates explicitly provide for ´aggregates from natural, recycled, and manufactured material´. The EU focuses on fitness of use and does not discriminate between resources. While recycled materials are not used in structural and foundation frames, they are extensively used in non-structural framework. Some member countries have reported that over 20 per cent of their national consumption is from recycled material.
UNITED KINGDOM: The Northern Ireland Environment Agency has published 'The Quality Protocol for the Production of Aggregates from Inert Waste in 2004'. This helped promote use of recycled and secondary aggregates. Almost 280 million tonne of aggregates are used every year, which is 28 per cent of C&D waste.
NEW YORK: This American city has stringent measures for C&D waste as it has limited space for disposal. Its disposal practices are more efficient than the rest of the US. It forces developers to segregate waste at site, and dismantle not demolish, in addition to other measures.
JAPAN: In 2000, Japan introduced the Construction Waste Recycling Law. It specifies the responsibility of contractors in sorting and recycling demolition waste when the total floor area of the building demolished is greater than 80 sq m. Demolition contractors are required to separate and recycle specific construction wastes such as concrete including precast plates, asphalt, and wood building materials. As far back as 2000, about 95 per cent of waste concrete was crushed and reused as roadbed and backfilling material, and 98 per cent of asphalt and concrete and 35 per cent of sludge was recycled.
FLANDERS: This region in Belgium introduced the use of secondary raw materials in the Flemish legal framework from 1997. It also developed a plan for C&D waste in 1995. This first policy plan for C&D waste introduced quantitative targets for the period 1995-2000. It aimed to recover 75 per cent of all C&D waste generated by 2000 and prevent its generation by 25 per cent in the medium term. The Flemish government is also planning to impose material use prescriptions by developing environmental profile of construction materials.
GERMANY: The country´s Act for Promoting Closed Substance Cycle Waste Management and Ensuring Environmentally Compatible Waste Disposal 1994 set principles for development of waste management to transition to a closed-loop economy. It lays emphasis on the prevention of waste generation rather than recycling of waste. The Federal Cabinet of Germany adopted the German Resource Efficiency Programme (ProgRess) in 2012. ProgRess also promotes recycling of C&D waste.
IRELAND: Ireland´s national waste policy aimed to achieve at least 85 per cent recycling of C&D waste by 2013. The country also published Best Practice Guidelines on the Preparation of Waste Management Plans for Construction and Demolition Waste Projects in 2006.
Civic Talk: Jaipur
¨C&D waste amounts to about 150 metric tonne per day.¨
Ashutosh AT Pednekar, Commissioner, Jaipur Municipal Corporation, shares the corporation´s plan to manage C&D waste.
Civic Talk: Bengaluru
¨About 1,000-3,000 metric tonne of C&D waste is generated per day.¨
Subodh Yadav, Special Commissioner, Bangalore City Corporation, shares the city´s initiatives to manage C&D waste.
Civic Talk: Pune
¨C&D waste of around 250-300 metric tonne per day is generated.¨
Omprakash Bakoria, Additional Municipal Commissioner (Special), Pune Municipal Corporation, elaborates upon the city´s initiatives to manage C&D waste.
Civic Talk: Bhopal
¨Waste generated is nearly 30-40 metric tonne per day.¨
MP Singh, Additional Commissioner, Municipal Corporation Bhopal, shares more on the city´s initiatives..