Introduction
As per Delhi Pollution Control Committee officials, the main reason, causing 30 percent of air pollution is all due to the dust that is eliminated from the construction sites. And, according to the Health Effects Institute’s report, it has been observed that a high rate of deaths are caused due to the air pollution containing dust and air pollution has become a third major cause of death in India.
Are you aware that why all of this is happening and for what all reason?
All of this is happening because of emissions from vehicles, dust releasing from construction sites, large power plants and refineries, vehicles, and stubble burning. In addition to it, the construction of new buildings, residential societies and ongoing projects have also been playing a crucial role that is resulting in damaging the air quality.
What can be done for avoiding the harm caused to our planet?
The National Clean Air Programme (NCAP) of India has made it easy and somewhat manageable to control the harm caused to our environment’s health. As under it, a target has been set of 20-30% reduction of pollution by 2024, taking 2017 as a base year. The National Clean Air Programme (NCAP) has come with the aim to:-
- Increase an effective ambient air quality monitoring network;
- Efficient data dissemination and public outreach management;
- Devising a feasible management plan for prevention, control and abatement of air pollution
All of this has been aimed with the hope to achieve the good air quality. Not only this, but for reducing the dust emission “Advancing Better Air Quality with Clean Construction” toolkit has been developed by the Clean Air Asia (CAA) to cure the same. In order to enhance the capacity building for stakeholders involved in construction activities such as Architects, Civil Engineers, Project Management Professionals, Construction Professionals, State Pollution Control Board and local governments.
Guidelines for reducing dust pollution
Construction and Demolition Waste Rules, 2016 prescribed various guidelines for all construction sites to prevent dust pollution in the capital city of India. The guidelines are as follows:-
- Dust/wind breaking walls of appropriate height around the periphery of the construction site.
- Installation of Anti-Smog Gun (s) (For > 20,000 sq.mt.)
- Tarpaulin or green net on scaffolding around the area under construction and the building.
- All vehicles including carrying construction material and construction debris of any kind should be cleaned and wheels washed.
- All vehicles including carrying construction material and construction debris of any kind should be fully covered and protected.
- All Construction material and debris of any kind should be stored on the site and not dumped on public roads or pavements.
- No loose soil or sand or Construction & Demolition Waste or any other construction material that causes dust shall be left uncovered.
- No grinding and cutting of building materials in open areas. Wet jets should be used in grinding and stone cutting.
- Unpaved surfaces and areas with loose soil should be adequately sprinkled with water to suppress dust.
- Roads lending to or at construction sites must be paved and blacktopped i.e. metallic roads (for > 20,000 sq. mt built-up area)
- Construction and demolition waste should be recycled on-site or transported to an authorized recycling facility and due record of the same should be maintained.
- Every worker working on construction and sited involved in loading, unloading and carriage of construction material and construction debris should be provided with dust mask to prevent inhalation
- Arrangement should be provided for medical help, investigation and treatment to workers involved in the construction of building and carry of construction material and debris related to dust emission.
- Dust mitigation measures shall be displayed prominently at the construction site for easy public viewing.
Preventive Measures
There are certain dust control measures designed for all types of activities to cure the air quality. Let us get to know about each of them in detail. The dust control measures are as follows:-
- Measures during demolition
| ACTIVITY/ SOURCE | CONTROL MEASURES |
| Debris during demolition | Construction site should be screened with appropriate screens or sheets as directed by CPCB/NGT/PCB at least 3m height or 1/3rd of the building height and maximum up to 10m |
| Before and during demolition | ASG machine made compulsory for > 20,000 sq.mt built-up area) Water/ chemical suppressant spraying should be carried out before and during demolition |
| Dropping materials to ground level | Enclose chutes, and skips will help in reducing dust emissions. Sufficient water supply needs to be carried out to increase the moisture content. |
| Removal of material from the site | Materials should be removed from the site right after finishing the task. Prolonged storage of construction debris on site or exposure to the wind should be avoided. |
| Crushing of material for reuse, transportation or disposal | Activities like crushing should be sited as far away possible from sensitive receptors |
| Asbestos | Asbestos needs to be removed before demolition |
| Biological material | Biological material should be removed before demolition. Due care must be taken so that the material does not become airborne, but is sufficiently contained |
2. Measures during material handling
| ACTIVITY/ SOURCES | CONTROL MEASURES |
| Material handling operations | Always keep the number of handling operations to a minimum by ensuring that dusty material isn’t moved or handled unnecessarily |
| Handling areas | Keep clean and free from dust |
| Vehicle loading | Use material handling methods that reduce the generation of airborne dust |
| Reduce dust generation by using water removal of materials from the site | Material needs to be removed from the site as soon as it is practical. Prolonged storage of construction debris on-site or exposure to wind should be avoided |
| Dust dispensary over the site boundary | Use static sprinklers, bowsers, handheld hoses and other watering methods as necessary |
| Chutes, skips and conveyor transfer points | Drop heights should be kept to a minimum and enclosed wherever possible to reduce dust generation with water |
| Transport of fine powdery materials | Vehicle must be fully covered and protected |
3. Measures during material storage
| ACTIVITY/ SOURCE | CONTROL MEASURES |
| Bulk Cement/fine aggregate material storage | Delivered by tanker or vehicle covered with a sheet stored in covered space |
| Accidental spillages when filling | Methods and equipment for cleaning must be in place. If necessary, include the use of audible and visual alarm systems. |
| Fine, dry materials (less than 3mm in particle size) | Store inside buildings or cover with adequate protection from the wind e.g. by using sheeting |
| Storage Location | Store material or stockpiles away from the site boundary and sensitive receptors whenever possible e.g residential, commercial and educational buildings, places of public access or other features, such as watercoures; |
| Storage/stockpiles protecting from wind erosion | Where possible, ensure stockpiles are kept enclosed or covered under sheeting. Dust generation from dusty materials can be reduced by using suitable and sufficient water sprays, wind barriers of similar sizes and height to the stockpile may be used. |
| Cleaning up | Clean up using wet handling methods. |
4. Measures during Operations (Cutting, Drilling & Sawing)
| ACTIVITY/SOURCE | CONTROL MEASURES |
| Cutting, grinding, drilling, sawing, trimming, planning, sandling | The following measures should be in place at all sites to comply with best practices: pre-wash work surfaces, screen-off work areas, and sweeping away Spraying water, preferably from a water efficient spray pump,over the material as it is being cut greatly reduces the amount of dust generated
Local exhaust ventilation should be used where possible for better health of workers |
| Façade Cleaning | Silica-free material should be used for abrasive cleaning since the inhalation of silica dust is harmful.
Wet processes should be used wherever possible. These introduce water into the air/grit stream, greatly reducing the dust hazard to both building occupier and the general public |
| Painting and decorating | Vacuum cleaning should be used wherever possible. Sanding and cutting machinery should be fitted with dust suppression or collection equipment |
| Fitting out-plastering, rendering, decorative finishing, furniture fitting | Cutting and sanding machinery should be fitted with dust suppression/ collection equipment Vacuum cleaning should be used whenever possible. |
| Cleaning process | Dry sweeping should be avoided and only carried out with vacuum extraction methods attached.
Washing and damping down should be carried out whenever required |
5. Measures during C&D Waste Management
| ACTIVITY/SOURCE | CONTROL MEASURE |
| C&D Activities | Use of ASG sand dust suppressant
Proper implementation of guideline on dust mitigation measures
Self-assessment through DPCC C&D Self Audit Web Portal |
| Storage | All areas for storing C&D wastes/ construction material needs to be demarcated and preferably barricaded particularly those materials that have potential to be dust borne.
Prohibiting open storage of C&D material and enforcement
Contractors/ builders/ sellers/ related stakeholders prohibited from storing/ dumping C&D wastes/ construction material on road as it obstructs traffic flow
Store any materials away from sensitive receptors in covered areas. Water sprinkling/ fine spray from nozzles to suppress dust re-suspension at site |
| Loading/Unloading | Areas where loading/ unloading (fugitive dust) activities to be demarcated and located should be in such a way that dust dispersal is minimized. |
| Reuse/recycle | Label all waste storage areas and skips, detailing the type of waste
Use recycled materials and recycle any materials used on site rather than disposing them which includes timber, aggregates, soil, tarmac, bricks, masonry, concrete and glass. |
| Deposition of construction waste | Every C&D waste generator must keep the construction and demolition waste within the premise or get the waste deposited at collection centre provided by local government or handover it to the authorised C&D waste proceeding facilities of construction and demolition waste; and ensure that there is no littering or deposition of waste. |
6. Measures during vehicle movement, routes & emission from vehicle
| ACTIVITY/SOURCE | CONTROL MEASURES |
| Construction and maintenance of unsurfaced roads & speed of vehicles | Keep roads/ ways in compacted condition using static sprinklers, commercially available additives. Suppressants All vehicle should be fully covered and protected Slow movement of vehicles generates less dust, introduce speed limits |
| Walkways and surfaces | Clean regularly using wet methods and not dry sweeping |
| Vehicle waiting areas and hard standings | Regularly inspect and keep clean by brushing or vacuum sweeping Sprinkle water regularly to maintain surface moisture if needed. |
