Poisonous Ammonia Gas Leak Near Ennore Harbour In North Chennai Port: 34 Hospitalised

A pipeline carrying Ammonia gas from the sea to a private fertilizer company in Ennore experienced a leak on Tuesday night, stirring panic among residents of Periyakuppam and Chinnakuppam. The strong odor of the chemical disrupted their sleep, prompting concern.

Although the gas leak was contained, by 3 AM on Wednesday, the levels of ammonia in the air and the sea surged to alarming heights. According to the Tamil Nadu Pollution Control Board (TNPCB), the ambient air's ammonia level reached 3 ppm (2090 micrograms/m³, well above the 400 micrograms/m³ 24-hour average). Additionally, the ammonia content in the seawater spiked to 49 mg/L at 3.49 AM, far beyond the marine discharge standard of 5 mg/L. Nearby areas experienced a mild ammonia odor, causing worry among residents.

This incident follows closely after an oil spill caused by the Chennai Petroleum Corporation Limited (CPCL) refinery wreaked havoc on the lives of Ernavur residents and fishermen, causing damage and health issues.

On Tuesday night, villagers woke up by the strong ammonia smell around 11:30 PM, resulting in breathing difficulties for many. Around 30 individuals were rushed to hospitals due to respiratory problems.

The gas leak occurred in the subsea pipeline of Coromandel International Ltd, known for manufacturing Ammonium Phosphate Potash Sulphate (APPS) and possessing a 12,500 T capacity double-insulated ammonium storage tank. The ammonia, generally imported from Iran or Saudi Arabia in liquid form at -330 C, is received via Ennore minor port and transported through an 8-inch flexible HDPE pipeline spanning 2.5 km beneath the sea bed.

TNPCB's preliminary observation noted a pressure drop in the pipeline around 11:45 PM, coinciding with the detection of a pungent odor near the storage terminal and the material gate. Gas bubbles were observed emanating from the pipeline, prompting immediate depressurization within 20 minutes by redirecting ammonia vapor to the flare.

During the incident, the ambient air near the material gate recorded an ammonia level of 28 ppm, leading TNPCB to instruct the unit to swiftly identify and address the pipeline damage before resuming ammonia transfer. Approval from the Tamil Nadu Maritime Board is mandated before reinitiating pipeline operations.