You've seen the thread about how Pepsi Cola got into trouble in Engkand when it leaked out that the Sassaani bottled water they were starting to try to sell to people was actually made from tap water in Peckham, and run through a filterinmg machine.

And then it turned out that in the process they were polluting it so that there were levels of bromate in it that were way above the safe maximum, and they had to recall the stuff and take it off the market.

There doesn't have to be a conscious worked out plan to pollute the water so as to make people buy bottled water. What happens is the companies sell the idea that bottled water is better for you than tap water, and as the proportion of people using it goes up, the idea that it doesn't really matter if the tap water quality goes down becomes politically acceptable.

It doesn't need any overall human conspiracy of people. The (guided) market works to change things to produce the profit-maximising result, because the drive for profit operates across the whole system. But not for everyone.