North China's Hebei Province, neighboring Beijing, is planning a purge of small polluting firms this year.

The provincial environmental inspection bureau said on Thursday that it would send inspectors to small firms in 10 polluting industries including paper-making, refining, leather-making, printing, pesticide manufacturing, dyeing and electroplating.

Companies found to have substandard environmental facilities will be closed by the end of 2016, according to a statement from the bureau.

The province will also subsidize coking, pharmaceutical, metals, leather-making and other plants to install facilities to clean their discharges, the statement said.

Hebei's new water pollution plan went into force earlier in February, promising the provincial government would invest 200 billion yuan (about 31.2 billion U.S. dollars) to battle water pollution by 2020.

More than half of China's 10 most polluted cities are in Hebei, whose pillar industries include iron and steel, cement and glass.