Abandoned shopping trolley

Whenever I go to Colinton Mains Park, I go for a dip in the burn. Every single time I go, there is at least one trolley in the water. Today there were three. How does that even happen? These are 'Tesco' shopping trolleys and we were under the impression that Tesco shopping trolleys had tags on their ankles wheels to prevent them from being taken out of their car park?? Obviously not!


To get to the park they have to be wheeled through at least 2/3 residential streets before being dumped in the burn in the park. This is obviously happening on a regular basis. Does nobody care?  The shopping trolleys we spotted today were obviously quite new because they were bright and shiny and not at all rusty.


…............That poses two questions................
We're guessing that every time Tesco loses a shopping trolley that cost is pushed onto the customer by raising the prices instore.
Who actually retrieves these shopping trolleys? Does Tesco employ someone to go and get them or is it down to the Council to keep the burn clean and free of debris?

Does anyone know the answer???????????????????????