Question & Answers on Soil Remediation
Question & Answers on Soil Remediation
Question & Answers on soil remediation
Who set the remediation standard?
The Tamil Nadu Pollution Control Board (TNPCB) - the statutory authority which has the responsibility of protecting the environment in the state of Tamil Nadu, where the site is located - set the remediation standard for the clean-up.
TNPCB had consulted with both the Scientific Expert Committee (SEC), which was constituted by the Supreme Court Monitoring Committee, and the Central Pollution Control Board – the foremost organisation that deals with issues concerning pollution control under the Ministry of Environment and Forests, Government of India – while deciding the remediation standard.
How was the remediation standard set?
In line with international best practice, a site-specific risk assessment was carried out at our former site taking into consideration human and environmental safety. Following this a remediation standard of 20mg/kg was set by the TNPCB. At this level, it will be fully protective of human health and the environment.
This standard had been confirmed by the Scientific Expert Committee (SEC), which was constituted by the Supreme Court Monitoring Committee, and has also been validated by the Central Pollution Control Board (CPCB) – the foremost organisation that deals with issues concerning pollution control under the Ministry of Environment and Forests, Government of India – to whom the TNPCB had referred the matter.
TNPCB had set the remediation standard basis review of extensive studies conducted by various eminent national institutions including National Environment Engineering Research Institute (NEERI), Indian Institute of Technology (IIT), Delhi, National Botanical Research Institute, Lucknow, and the Central Soil and Water Conservation Research & Training Institute, Ooty.
Why is remediation work pending even after so many years?
We remain fully committed to cleaning up the soil at our former factory and are eager to start work as soon as possible.
This has been a longstanding issue, dating back to 2001, when it was found that glass scrap with residual mercury had been sold to a scrap dealer in breach of our guidelines. HUL immediately closed the factory and launched an investigation.
There was no adverse impact on the environment except in some areas within the factory premises which required remediation. This has been confirmed by many independent studies.
We sought permission as early as 2002 to begin the soil remediation, but it was not until 2007 that we received in principle approval to start work after a full analysis was carried out by NEERI.
During the intervening period, other remedial measures such as the export of mercury bearing material to US in 2003 and decontamination and disposal of plant and machinery in 2006 were undertaken.
Soil remediation work began in 2009, but was stalled the following year after some activists contested the clean-up standard – resulting in further studies being carried out by national institutions to assess the impact on matters such as tree preservation and soil erosion.
An additional Risk Assessment Study and review of the site specific clean-up standard was also carried out by IIT Delhi. The culmination of these studies – and visits by the TNPCB and the Scientific Experts Committee (SEC) to Kodaikanal – was the reconfirmation of the TNPCB set 20mg/kg standard by the SEC in 2013. The TNPCB referred this matter to the CPCB, who endorsed the standard of 20 mg/kg in 2015.
In 2015, Hindustan Unilever submitted a Detailed Project Report for soil remediation to the TNPCB, based on the soil remediation standard as recommended by the SEC.
On December 31, 2016, HUL received permission from TNPCB to commence preparatory work and trials for soil remediation at former factory site in Kodaikanal.
On August 16, 2017, HUL commenced soil remediation on a trial basis at its former factory site in Kodaikanal. The trial was conducted for a period of three months and was successfully completed in November 2017 in accordance with the Detailed Project Report and as per the approval given by TNPCB.
In February 2018, HUL submitted the final soil remediation plan for remediating the soil inside the factory premises to the TNPCB.
On June 11, 2018, Hindustan Unilever Limited (HUL) received permission from Tamil Nadu Pollution Control Board (TNPCB) to commence full scale soil remediation to the remedial standard of 20mg/kg at its former factory site in Kodaikanal. HUL is committed to cleaning up the site.
On November 1, 2018, the Principal bench of the NGT, Delhi cleared the way for soil remediation at HUL’s former factory in Kodaikanal. The NGT also reaffirmed the soil remediation standard of 20 mg/kg.
The decision of the National Green Tribunal was challenged before the Supreme Court of India. In March 2019, the Supreme Court dismissed the petition and allowed the soil remediation to go ahead.
HUL received the Consent-to-Establish from Tamil Nadu Pollution Control Board (TNPCB) and is now in the process of installing and commissioning the remediation equipment and establishing facilities to undertake soil remediation. HUL will commence full scale soil remediation upon receiving a Consent-to-Operate from the TNPCB.
Why not go below 20 mg/kg?
- The TNPCB set and CPCB approved 20mg/kg standard has been reached following internationally recognised best practice for determining site specific remediation criteria.
- There is no science to back any reduction in the site specific remediation criteria, as it is not based on any site-specific risk assessment.
- A remediation to the Canadian Soil Quality Guideline would not be any more protective to human health and the environment than a remediation to the site-specific mercury remediation standard.
- A lower standard will lead to greater ecological and environmental damage on account of greater soil excavation and will lead to soil erosion & ecological imbalance in the hilly terrain where soil content is not uniform.
- We estimate that 300 trees will be affected / removed if the standard is 20 mg/kg as set by the TNPCB and approved by the CPCB. If the standard is taken to 6.6 mg/kg (as currently suggested by activists based on current Canadian Soil Quality Guideline), the number of trees affected / removed will be an estimated three to four times that number.
- Similarly, we estimate that the area to be excavated would be approximately 10,000 m2 if the standard is 20 mg/kg as set by the TNPCB and approved by the CPCB. If the standard is taken to 6.6 mg/kg, the area to be excavated would be around five times more, causing significantly greater disturbance to a fragile ecosystem, with implications for soil run-off and landslides.
Are there international remediation standards for the clean-up of mercury-contaminated sites?
There is no single remediation standard for the clean-up of mercury contamination either in India or any other country.
Some countries have established preliminary screening criteria, which are used by regulators to determine whether a site is potentially contaminated or not and whether a site-specific clean-up standard should be established. These criteria vary from country to country and are different to the standards which regulators set when remediation is required. Remediation standards are based on a risk assessment study of the site in accordance with international best practice. The US Environmental Protection Agency, UK Environment Agency and European Environmental Protection Agencies follow this approach.
Some activists have claimed that 6.6 mg/kg is the remediation criteria that should be adopted for the site. What is your view?
The Ministry of Environment & Forests (MOEF), Government of India, has not issued any document which proposes 6.6 mg/kg as the remediation standard.
Tamil Nadu Pollution Control Board (TNPCB) has set the remediation standard based on site specific risk assessment study. This has been done as directed by the Supreme Court Monitoring Committee. Even the guideline issued by CPCB in 2015 mandates site specific risk assessment for deciding remediation standard for remediating contaminated sites.
The TNPCB had in May 2015 stated that the Site Specific Target Level (SSTL) for our former factory in Kodaikanal should be 20 mg/kg after this standard had been validated by the Central Pollution Control Board (CPCB) – the foremost organization that deals with issues concerning pollution control under the Ministry of Environment and Forests, Government of India – to whom TNPCB had referred the matter.
Arbitrarily lowering the remediation standard without any scientific basis can result in risks to the local ecology whilst not providing any additional benefit.