Liability, responsible problem Shared terrain

Questioner

I would like to submit the following with the question of what is correct. Perhaps you already have some advice or someone who can help me with this I have a building on a business site: (shared) Part of the sewerage system has been replaced due to blockages, so that the entire paving does not have to be opened every time. Only not at the height of my building, sewerage shared with neighbors. My tenant has already had several blockages. These are not in the toilet or in/under the building, but appear to be at the height of 'neighbours': Cause of wipes in poorly running/narrow sewer. Tenant claims high and low not to use wipes. However, she does have recurring problems (and bills) with the complaint that the toilet bubbles or does not drain. So now for the third time. Now the tenant indicates: I use the toilet correctly: no objects that are not allowed) in the toilet in combination with the feedback from the sewerage company (it was ALSO indicated that it is a narrow sewer) She therefore decided that it was no longer her problem and had the unblocking invoice sent to the VvE. VvE indicates: wipes problem: So user problem. they send invoice to me. I have had email contact about this. The VvE thinks that we should first resolve this with neighbors that I do not know/know, and who are hardly there. Approaching these parties myself is not something that feels comfortable or right for me. The problem is that our building/toilet is used daily. There is little daily activity among the neighbors - They will not encounter this toilet problem every day. - Low usage is not conducive to traffic flow. - Incorrect usage cannot be traced I wonder: What can I expect from the VvE? And to what extent am I liable and responsible? What is wisdom now? Where can this problem be structurally resolved? It is untenable for both her and me to have it unclogged every time for €450. And the problem cannot be solved structurally because no one takes responsibility for the problem and no one can be held directly liable. Furthermore, the blockage is at the level of the neighbours and it is not possible to prove who the wipes belong to. I as the owner feel responsible and also the weakest link. Both expect me to solve it. By the way, the toilet is bubbling again and I foresee that this will remain a recurring problem. It is not resolved by paying the invoice once. What is possible and what is wise? Thank you very much in advance

Lawyer

The VvE rightly states that the cause is the wipes, but I think it is also a problem or it could be the installed piping. There is evidence of incorrect use because wipes were found and they are not allowed to go down the toilet. The other owner is therefore not behaving as a good owner. I think that there is also a servitude on or under the shared wall and that you should write to the other owner about the behavior of his tenant, or hold the tenant himself liable for the damage of unnecessary unblockings due to abnormal use.