In West Bengal the water has less than 0.05 mg/l arsenic in most places.

In Telangana most wells have worse water than in Madhya Pradesh.

In the pink areas the water is more poisonous that in the purple areas.

There are more that ten places where there is no arsenic in the wells in India.

There are more poor quality wells in Bihar than in Jammu& Kashmir.

Most wells, but not all have good quality water in Odisha.