For two days now water supplies to 200,000 people in Shuyang county of east China's Jiangsu Province have been halted because ammonia and azote were discharged into a local river.

Harmful substances were detected in the water at 3:00 p.m. on Monday and the level of 28 mg per cubic meter is about three times the upper limit for drinkable water.

An initial investigation indicated the pollution could have been caused by industrial sewage from chemical plants on the upper reaches of the Xinyi River, which originates in Shandong Province.

The county government said it was unable to tell when supplies would resume because the environment watchdog was yet to pinpoint the source of the pollutants before measures could be taken to curb the spill. They are seeking help from Shandong to trace the pollution source.

Alternative water supplies from 33 unpolluted wells have been arranged in the mean time, a spokesman with the county government said.

The county has also claimed it is diverting water from Hongze Lake into local water sources to dilute the pollutants.