Why we need to restore contaminated land
Even after 21 years of waste management legislation, a majority of local urban organizations do not have a technical landfill for the disposal of inert and residual solid waste.
Many ecosystems are at a breaking point due to the mismanagement of resources by human activities. The theme for World Environment Day 2021 – “ecosystem restoration” – means restoring degraded or destroyed ecosystems and conserving those that are still intact and are an integral part of nature.
This is fundamental because thriving ecosystems provide services such as food, water, nutrient cycling, climate regulation, biodiversity conservation and important greenhouse gas sinks.
As stated by the United Nations Environment Program, restoration alone can provide one-third of the mitigation by 2030 to keep global warming below 2 degrees Celsius and help societies and economies to s ” adapt to climate change.
The restoration of ecosystems can be achieved thanks to the 3 Rs: Recovery, Revegetation and Rehabilitation ”. Therefore, in the current scenario, we need to ensure that our degraded aquatic and terrestrial ecosystem is restored as soon as possible by adopting appropriate policies and technological interventions.
Nearly 10,000 hectares of precious land have been occupied by municipal solid waste landfills, according to the Central Organization of Public Health and Environmental Engineering. This poses a threat of irreversible damage to the environment and many other health risks.
As identified by the Central Pollution Control Board (CPCB), more than 3,000 landfills in the country are in urgent need of remediation and rehabilitation. Swachh Bharat Mission 2 has set itself a specific objective of cleaning up landfills.
However, even after 21 years of legislation on waste management, a majority of local urban organizations do not have a technical landfill for the disposal of inert materials and residual solid waste (generated by waste treatment units) and an appropriate separation and treatment mechanism to manage their municipal waste.
As a result, most of the waste is disposed of without being treated.
In addition, the CPCB has also identified and confirmed 112 contaminated sites that need to be rehabilitated and restored. These contaminated sites are “demarcated areas in which the constituents and characteristics of toxic and hazardous, man-made substances exist at levels and under conditions which pose existing or imminent threats to human health and the environment. », According to the CPCB definition.
These sites can be in residential, commercial, agricultural, recreational, industrial, rural, urban or wilderness areas where the main contaminants could be heavy metals such as hexavalent chromium; halogenated hydrocarbons; asbestos; phenolic compound; sulfate; chloride, etc …
These sites potentially include production areas, waste storage sites, processing sites, tailings sites, landfills, landfills and dumping sites. Examination of preliminary data shows that the site areas vary from a few thousand square meters to over 20 hectares to 49 acres.
Numerous studies have reported that the main reason for land contamination is the unscientific disposal of hazardous wastes, effluent discharge and the dumping of other wastes, including wastes mixed with municipal solid wastes. Most of these contaminated sites, including waste landfills, have not been remediated for many years and continue to pose a multi-faceted threat to health and the environment, including contamination of soil, groundwater and landfills. surface water.
Thus, it becomes the responsibility of the state in the wider public interest to protect the recipient population from the dangers of contaminated sites.
It is essential to note that the remediation of contaminated sites involves the cleaning of contaminated environments, i.e. groundwater, surface water and sediments, by adopting various remediation technologies in situ or ex situ. to achieve predefined sanitation target levels for each identified item. dangerous contaminant.
These site-specific remediation targets should be decided for each site, separately adopting either the risk-based assessment approach or the standards-based approach. Various factors must be taken into account before remediation, such as the type of future land use envisaged and the techno-economic feasibility of the remediation technology in order to ensure ecological restoration of these in the future. .
Some efforts have been made in this area by the Government of India. It appears that a remediation project of 12 contaminated areas in eight states – Kerala, Madhya Pradesh, Odisha, Tamil Nadu, Uttar Pradesh, West Bengal, Rajasthan and Gujarat – having multiple sites is being carried out via CPCB at cost of Rs 805 crore with funding 40 percent from the National Clean Energy Fund and 60 percent as contribution from state governments.
Likewise, a capacity building program is being implemented by the World Bank to strengthen the knowledge base and technical know-how of state governments to undertake site remediation works.
However, it was recognized that there was a lack of experience and expertise in the country in remediation of contaminated sites. In addition, the existing institutional and legal framework of the country does not impose the implementation of responsibilities on the responsible parties, cost recovery and execution of sanitation works.
Hazardous and other waste management rules, 2016 and solid waste management rules, 2016 oblige the state to protect and safeguard the environment and health risks resulting from poor waste management with sustainability long term, but there are no clear management strategies defined at national level for local level with regard to contaminated sites.
This calls for an urgent need for political (as well as technological) intervention and guidelines to help pollution control authorities manage contaminated sites effectively.
In addition to the identification and assessment of contaminated sites, appropriate technological intervention, financial and technical support mechanisms, modernization of existing disposal facilities, as well as monitoring and compliance to restore contaminated sites in the country are needed, which will serve the overall program of ecological restoration and climate change.
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