The water in the wells of Xiaozhuzhuang Village in Cangxian County turns into red. [File photo]

But the plant is licensed for discharges, according to the environmental protection bureau, and a principal of the plant claimed that local environmental departments examine sewage from the facility every year, with results proving the water could meet the standards.

However, villagers said they had taken water samples for testing, and the results showed that the water samples contain aniline and nitrobenzene, a poisonous oily water-soluble liquid.

Earlier in January, a poultry farmer surnamed Zhou reported the death of around 700 chickens on his farm, attributing the disaster to the animals' drinking of the red underground water.

According to villagers, shallow local groundwater began to turn red in 2002. In the beginning, they only found the red tint in a 30-cm-deep puddle, but later the water in a 400-meter-deep well began to turn pink as well.

Since then, people in Xiaozhuzhuang have only been able to use purchased purified water for drinking or cooking.

According to the local government, Jianxin Chemical Plant was built in 1988. Its main product was metanilic acid, but the plant halted production in 2011.

The government didn't disclose why the plant halted production.

The county government has launched a team to investigate the pollution, and villagers have been warned against drinking shallow groundwater or allowing livestock to do so.