CAN WE BE SURE?

There is no such thing as zero risk — it is a risk to get out of bed in the morning but probably a greater risk not to. We can, however, reduce risk to an acceptable level.

It is relatively easy and inexpensive to remove 99% of pathogens or pollutants from water but it costs a lot more to remove 99.9% of them and much more again to remove 99.99%. As we continue to purify the water it costs an ever-increasing amount of money to remove everdecreasing amounts of pollutants. Eventually there is so little left that we cannot detect it — the stage is reached where the risk is reduced to a point where it is insignificant and further expense is not justified.

As we continue to purify the water it costs an ever-increasing amount of money to remove an ever-decreasing amount of pollutants.