To avoid contamination, Wells in the Bengal Basin can be drilled into deep layers that were oxidized during the last ice age, in which the water is free of arsenic, Berg says.

为了防止被污染，孟加拉盆地的水井钻入了在上一个冰河时期被氧化的深层地层中，这一层的水是不含砷的，伯格说。