Excess construction sand classified as "waste"

Hello everyone.

The base slab has been poured and the earthworks contractor/foundation slab manufacturer has now left various waste materials on the property. As the client, I am contractually obligated to dispose of these, so far so good.

But: what exactly counts as "waste"?

Besides the usual materials such as concrete leftovers, KG and drainage pipes, Styrodur cut-offs, packaging and wooden parts, the earthworks contractor also left about 15 tons of construction sand. This was ordered for the substructure but was not completely used. My question: does this now also count as "waste"? Or is he obliged to take the excess material back with him?

The construction sand is naturally a double burden for me, as I have paid for the material without using it and now also have to bear the costs of disposal.

Until these and other questions are clarified, I do not want to transfer the final invoice yet. Since the due date will soon be reached, I am also wondering how I should best behave legally. Is an email stating that I do not agree with the invoice sufficient, or should I rather contact him by mail and even by registered letter? Do I have to provide a precise reason for what I believe is incorrect?

Thanks in advance

Depending on the contract, that is already included. You should post the exact wording here.

But to be honest, I think you will still be able to use it or if you put it up for free in the Minibucht, you'll get rid of it faster than you can say specialist lawyer for construction law.

I would also say that you will easily find a buyer for it. Just list it for self-pickup at symbolic prices.

Exact wording according to the contract:

i. to dispose of excavation and waste remaining after the construction work at own expense

I really don’t understand why someone would sign something like that, but as I said, sand is no problem.

I have already advertised on eBK (is that the "Minibucht"?) accordingly. Unfortunately, no interested party has been found yet. Problem: there is very little space on the property and the stuff has to be gone in 4 weeks at the latest, because the (finished) house will be delivered. Even if I want to move it to the farthest corner, a mini-excavator has to come (another 500 euros cost)...