A large area of contaminated water has been found off the coast of Eastern Shishi City, China.

The plume of black water which is estimated to be the size of 50 Olympic swimming pools was discovered by Greenpeace and has been found to contain toxic chemicals including heavy metal and Nonylphenol – a hormone disruptor.

The pollution is believed to be caused by discharge from factories. The discharge pipe of an industrial zone lies under the sea surface in the contaminated area. The pipe belongs to the Haitian Environmental Engineering Co. Ltd, a communal wastewater treatment plant.

“This is not an isolated case. Among 435 registered discharge points, more than two thirds were caught violating environment standards in 2012, and one in every four of them never met the standards at all. In this case, the communal wastewater discharge pipe is 2.4km long and buried deep down the sea – that’s how far polluters are willing to go to hide their dirty secrets,”says Greenpeace East Asia toxics campaigner Lee Chih An.

Greenpeace activists have submitted the findings of their investigation into the matter to the Chinese government, calling them to take action.