Press Release: Unilever’s Cuts 300 Trees; Exposes Contaminated Soil; Triggers 100 kg Mercury Discharge into Kodaikanal Wildlife Sanctuary

19 August, 2021. Chennai — At least 100 kg of soil-bound mercury is likely to have been washed off into the ecosensitive Pambar Shola section of the Kodaikanal Wildlife Sanctuary since Unilever illegally chopped down more than 300 trees from 4 acres of its heavily contaminated factory site in January 2020, a study done by Chennai Solidarity Group revealed. Removing protective vegetative cover from the most contaminated portions of its factory site has exposed the toxic soils to erosion by rainwater and wind. Local residents are complaining of health effects due to dust that invades their homes with the prevalent winds. Mercury is a potent poison that can build up from seemingly insignificant levels in environment to lethal loads in the top predators in aquatic food chains. The now-closed mercury thermometer factory is located on an erosion prone slope draining into the Pambar River that runs through the sanctuary and joins the Vaigai in Periakulam plains.

Unilever factory site in March 2018

Unilever factory site in January 2020 after the illegal cutting of more than 300 trees from 4 acres of its heavily contaminated factory site

“This clear-felling is a reckless move that will allow Unilever to “clean-up” its site by poisoning the Wildlife Sanctuary and the Vaigai catchment. The Forest Department and TNPCB stand exposed as incapable of protecting the sanctuary and environment,” said Nityanand Jayaraman of Chennai Solidarity Group. Releasing Google Earth imagery before and after the deforestation, the Group called for immediate intervention to cover the contaminated site to mitigate soil discharge into the sanctuary before the onset of the northeast monsoon in October.

In 2018, TNPCB approved an Upscaled Remediation Plan prepared by Unilever’s consultant NEERI and directed HUL to additionally follow the guidelines issued by Soil and Water Conservation Research and Training Institute, Ooty. The soil conservation study insists that no tree should be felled, and recommends measures to ensure that standing trees are not destabilised due to excavation of contaminated soil. This violation was supervised by NEERI which has been deputed onsite to ensure that remediation goes as per the plan prepared by it. Civil society actors had pointed out that TNPCB should not outsource monitoring to a consultant paid by the polluter. NEERI is Unilever’s paid consultant.

“Palni Hills experiences heavy rainfall. Upto a few 100 mm can fall in a day with much of it falling in a few hours. Even with vegetation cover, significant soil run-off should be expected. Removing trees and vegetation from these erosion-prone mercury tainted slopes is a recipe for disaster with devastating impacts on residents in the neighbourhood and the sanctuary’s wildlife,” said Dr. Jagdish Krishnaswamy, a forest hydrologist and scientist with Bengaluru-based ATREE.

CSG’s study estimates that even with protective vegetative cover, 5.25 kg of mercury was leaking into the shola each year. After removal of vegetation in January 2020, that rate increased to 66 kg. At these rates, more than 100 kg of mercury is likely to have been discharged to Pambar Shola in the last 20 years before the trees were felled. An additional 100 kg is estimated to have been discharged just in the three monsoon seasons between January 2020 and July 2021. Unilever has avoided monitoring rainwater discharge from its site despite being legally required to do so. TNPCB and its expert committee too have taken a lenient view of the matter.

In 2002, Unilever’s consultant estimated that only 366 kg of mercury remained mixed in the soil onsite. These figures are unreliable. However, TNPCB has refused to independently verify this figure. Unilever’s unambitious remediation plan aimed to remove only about 200 kg of mercury from the soil. If Unilever’s figures are to be believed, then remediation is already complete as 200 kg of mercury has been washed off into the sanctuary as per the findings of the study. If, on the other hand, substantial quantities of mercury can still be found in the site, then the studies carried out by NEERI and other consultants are wrong.


  • In 19 years between 2001 and 2020, 100 kg of mercury has leaked into Pambar Shola.
  • In 18 months between January 2020 and present, another 100 kg of mercury has leaked into Pambar Shola.
  • Soil erosion and release of soil-bound mercury has increased 12 fold because of clearfelling and clearing of vegetation from 4 acres of most contaminated factory grounds. Company’s claim that mercury was contained within the site and was not leaking offsite is wrong. Mercury was leaking into the Pambar Shola at a rate of 5.25 kg/year with vegetation. After clear-felling, mercury leaving contaminated site is about 66 kg/year.
  • Clear-felling is in violation of laws. Factory site fell within 10 km Eco-sensitive Zone of Kodaikanal Wildlife Sanctuary. Tree felling and handling of mercury within factory site required permission from State Government and National Board of Wildlife.
  • NEERI, TNPCB and Forest Department have allowed the discharge of at least 200 kg of mercury into Pambar Shola by a known offender despite being warned against it.

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Nityanand Jayaraman