Tata Chemicals, which is primarily into manufacturing of salt, chemicals and fertilisers, has written to the CPCB for rescinding the order. It has submitted the reports of parallel samples, which was drawn on the same day as CPCB, confirming the compliance with the prescribed norms by the State Pollution Control Board approved lab.

"On March 11, 2017, the company has received a notice from the Central Pollution Control Board (CPCB) directing the company under Section 5 of the Environment Protection Act, 1986 to shut down plant operations at Haldia, West Bengal for alleged non-compliance with the prescribed norms for liquid affluent discharge," Tata Chemicals said in a BSE filing. This order was based on the analysis of sample drawn on January 9, 2017, by CPCB which alleges to have breached the prescribed norms for discharge of effluents, it added.

"The company has made a written representation to CPCB to rescind the order. The company in its representation has submitted the reports of parallel samples drawn on the same day as CPCB confirming the compliance with the prescribed norms by the State Pollution Control Board approved lab," the filing said.

In addition, Tata Chemicals has also submitted the reports of independent labs approved by the Ministry of Environment & Forest and West Bengal Pollution Control Board which has confirmed that the levels are within the norms. Tata Chemicals had last month said that Haldia plant would remain shut till April 15 due to relocation of ammonia pipeline as well as annual repair and maintenance work.

The fertiliser plant at Haldia manufactures DAP, SSP and complex NPK fertilisers wherein ammonia is used as one of the feedstock.