Council on Energy, Environment and Water Integrated | International | Independent
India’s national capital region often sees construction prohibitions when pollution levels become especially concerning in winter months. However, with well-planned construction schedules all year round, we can take a proactive approach to minimising losses from regulatory bans and improving air quality.
In India, the construction sector is estimated to account for approximately 13 per cent of the country's economy. In 2023, it was the sixth-largest foreign direct investment recipient sector. In the fiscal year 2022-23, the sector experienced notable growth, driven by substantial investments in infrastructure and real estate development.
While this sector is a large contributor to GDP, it is one of the main causes of urban air pollution as well. Industry, a large component of which is construction, is responsible for 20-30 per cent of all air pollution. This is because construction activities emit large amounts of particulate matter (PM) into the atmosphere, particularly PM10 and PM2.5, which cause severe environmental and public health impacts. As per source apportionment studies, in Delhi, the construction sector contributes 8.4 per cent of PM2.5 and 20.8 per cent of PM10 emissions; similarly, in Mumbai, it accounts for 9 per cent of the total PM emissions.
The government of India has undertaken several measures to decrease the air pollution crisis from various contributing sectors. The Commission for Air Quality Management (CAQM) has implemented the Graded Response Action Plan (GRAP) in Delhi NCR to regulate air pollution levels. This plan essentially targets high-polluting sectors (like construction) and imposes restrictions on their activity during times of high pollution. To determine which measures are imposed at a given time, the severity of air pollution is categorised into four successive stages based on the Air Quality Index (AQI). The stages are as follows:
How does this affect construction? During the earlier stages of poor air quality, the government may enforce measures such as the use of anti-smog guns, water sprinklers, and dust suppression measures in construction sites. In the fourth ‘severe’ stage, the government may impose blanket bans on construction activities to improve local or regional air quality. For instance, on 2 November 2023, the Delhi government placed a 41-day blanket ban on construction activities due to severe air pollution levels. This interruption likely delayed construction project schedules by 3-4 months.
However, the imposition of these regulations comes with several challenges.
During winter in northern India, severe spikes in air pollution levels are observed due to varied local and transboundary pollutants fused with meteorological conditions. Restrictions and bans on construction activities are inevitable during that period. For construction companies, the financial losses of such bans on work can be severe, including penalties, project delays, increased project costs, and reputational damage. These bans also affect the livelihood of daily wage construction workers. Due to unemployment, they are often forced to migrate. Strategic planning is required to safeguard against the negative impacts of such bans. Thus, effective dust mitigation measures must be incorporated into project schedules from the very beginning.
Several measures, such as the usage of water sprinklers, anti-smog guns, dust suppressants, covering materials, and installing barriers, are essential to control dust. At the construction site, it is the duty of the site manager or contractor to ensure their implementation. These measures are largely used in the short term when restrictions have been imposed by authorised commissions rather than being followed all year round. However, if dust mitigation measures were considered at the scheduling stage of any construction project and used year-round, the gradual rise of emission levels in and around the site could be controlled.
To explore the potential benefits of implementing these safeguards from the beginning of a project, the Council on Energy, Environment and Water (CEEW) has initiated a pilot study with Signature Global (India) Ltd at a construction site (~ 9 acres) in Gurugram. This study involves setting up monitoring tools to evaluate the intensity of dust emissions from different construction activities and assess the effectiveness of mitigation measures.
Certain activities generate high dust emissions and increase air pollution levels in and around the site. They are called pollutant-intensive activities. These activities include excavation, demolition, earth filling, material transportation, and vehicle movement on unpaved roads. Further, it has been observed that implementing mitigating measures for the aforementioned activities could result in a considerable reduction in PM concentration levels. Evidence for the same can be seen in the graphs below.
The graph on the left displays the effects of pollutant-intensive and non-pollutant-intensive activities on air pollutant concentration. Pollutant-intensive activities cause a considerable rise in pollution levels, whereas non-pollutant-intensive activities cause minimal variation in pollution levels from the baseline (where no activity is involved). The graph on the right illustrates the effectiveness of a dust mitigation measure, i.e., water sprinkling. It was observed that water sprinkling was effective in reducing the increasing concentration levels by ~45-70 per cent for a specific duration of time (~ 3-4 hours).
Careful planning and execution of construction projects are critical. This should account for three things.
Rule 1: Incorporate dust mitigation plan into project schedule
Most construction companies begin projects by using a Work Breakdown Structure (WBS) to develop a schedule and estimate the costs and duration of each activity. One way to get builders to prioritise clean construction methods, reducing delays and additional costs associated with dust-related issues, is to necessitate the incorporation of a dust mitigation plan in the construction schedule when a project is awarded. Dust mitigation plans involve various activities and measures such as the use of anti-smog guns, green covering, high-height barriers around the construction site, and regular frequency of water sprinkling. Measures such as using water sprays and windbreaks are also common.
Rule 2: Plan according to the type of project
Most dust-generating activities and associated fugitive emissions occur during the excavation phase of greenfield construction projects (where new developments are built on previously unused land). Including a dust mitigation plan as a sub-task during this stage ensures that the necessary time for these activities is already accounted for, preventing unexpected delays. Similarly, for brownfield sites (land previously used for industrial or commercial purposes), allocating time and budget for dust mitigation during the demolition phase can prevent costly emergency measures, such as firefighting.
Rule 3: Monitor implementation
During a project's progress monitoring and reporting, the Environmental Health Safety (EHS) team should ensure dust control and suppression activities, as specified in the dust mitigation plan, are tracked and updated to ensure compliance. With a clear plan in place, compliance enforcement becomes smoother, reducing the need for immediate responses to regulatory construction bans and avoiding associated penalties.
The construction and real estate industry is already taking proactive measures at their sites for dust control and pollution reduction. However, the emergency firefighting during GRAP measures is leading to unaccounted delays and costs for builders. Thus, they are looking to incorporate a well-scheduled and phased dust mitigation plan throughout the construction lifecycle at their sites. This also benefits air quality.
Similar to our pilot study, we've seen recent successes at various construction sites in the Delhi NCR region where proper dust mitigation measures have been employed. A notable example is the comprehensive approach implemented by the Delhi government through a set of 14-point guidelines aimed at curbing dust pollution. The government launched a web portal to facilitate self-monitoring of compliance with these dust control guidelines. This portal requires construction project proponents to self-audit and upload their compliance reports fortnightly. The system allows for easier monitoring and enforcement, with provisions for scoring compliance and imposing fines through the portal itself if guidelines are violated.
As Sun Tzu said in The Art of War, "All things being equal, the Winner will be the General who spends more time in planning." This holds true for India’s construction sector.
Mohammed Sahbaz Ahmed is a Research Analyst, Faiza Khalil is a Consultant, Surya Shekhar Auddy is a Research Analyst, and Arpan Patra is a Programme Associate at the Council on Energy, Environment and Water (CEEW). Send your comments to [email protected]
Add new comment