Hi Bruno,
So pleased to read about your new garden! The Bamboo clearance sounds like Zen work to me, worthwhile and time-consuming.
With the possibly contaminated soil, two thoughts – 1. raised beds? 2. Ask the Gemeente if they have details of soil quality there, or they may even offer a testing service.
Sounds a good plan to remove top soil and replace. In Amsterdam locations with serious contamination (there’s a park sculpted on top of a previous hazardous rubbish dump – Diemerpark), they encapsulate the contamination with an impermeable liner and then put new soil on top. Not really something for a back garden, but plant roots will go deep sometimes, into the old soil, so keep that in mind. Hence the idea of raised beds for areas in the garden where you really want to grow food.
Good luck with it! I am looking forward to learning how the garden progresses 🙂