The remediation efforts undertaken at a site in Kodaikanal where Hindustan Unilever (HUL) once had its thermometer factory are once again embroiled in controversy with activists claiming that the process is a “failure”. However, the company has stoutly denied the charge.
A report by the Chennai Solidarity Group has urged the Tamil Nadu Pollution Control Board (TNPCB) to commission a fresh Detailed Project Report (DPR) to remediate the site.
The report titled ‘Evaluation of Unilever's Trial Remediation of Mercury-contaminated Soils in Kodaikanal, Tamil Nadu’, a copy of which is available with The Hindu , alleges that remediation trials carried out between September and November 2017 “were a failure, and the reporting of the data from the trials is incomplete, inconsistent and unreliable.”
HUL, in its response to The Hindu, however, denied all the charges, and said: “The soil remediation trials tested the efficacy of the remediation process using the pilot plant installed at the factory . Further, the learnings from the scale trials were used for finalising the full-scale remediation plan.” The company said the data was complete, reliable and verified by the National Environmental Engineering Research Institute. The Chennai Solidarity Group also said that a mercury balance prepared by it while preparing the report, found that soil washing with water converts a soil mercury problem into a water mercury problem “with the associated and heightened risk of biomethylation of mercury into its more toxic methyl mercury form.”
HUL said soil washing was an accepted technology in Europe and demonstrated to be a successful technology. “During the entire trial, all the water used for soil washing was treated and reused in the process. The quality standards were monitored, and it was ensured that they were within the permissible statutory limits,” HUL said. The company reiterated that the remediation work would be monitored by the Scientific Experts Committee (SEC), constituted by the Supreme Court Monitoring Committee and the TNPCB.
The report further said that the TNPCB had authorised the company to demolish the buildings and decontaminate machinery without evaluation of the processes or their environmental impact. “This will prove to be a disaster as the process will not only mobilise large quantities of mercury into the Kodaikanal Wildlife Sanctuary, but also enable its conversion into the bioavailable and more toxic methylated form.”
To this, HUL said the buildings in which mercury was used would be demolished.