Yep, its a classic problem of externalities. The pollution caused by plastic bottles, and the cost to clean them up, are not paid for by the people buying them

Yep, its a classic problem of externalities. The pollution caused by plastic bottles, and the cost to clean them up, are not paid for by the people buying them. 10c tariff for every individual plastic item should solve the problem. Use the money to fund public water fountains, and 5c to whomever hands in the bottles to be recycled.