Ban supermarkets from selling large bottles of water in shrink wrap of 6

Supermarkets are selling stacks of large shrink wrapped bottles of water. The people buying these often come from countries where tap water quality is not good-they don't realise that the tap water in this country is good. They may be people who are struggling to pay their bills and this is an extra and unnecessary expense. If there is concern about water, then the solution is to buy a water jug with a filter which removes most impurities and which cost very little. Supermarkets could encourage their purchase by doing special promotions alongside the water.