Pumping system or natural drainage over a 40m channel

Hello everyone,
for our new building on a hillside, we need a pumping station to reach the sewer in the upper street.
Optionally, one could go through the neighboring property to the sewer in the parallel street below the building. However, pipes of about 40m would have to be laid here.

What do you think? What makes more sense in terms of costs (purchase and installation/maintenance of the pumping station vs. laying pipes)?

What do you think? What makes more sense in terms of costs (purchase and installation/maintenance of the lifting system vs. laying pipes)?

You only know that once you have concrete offers. Pipes on the neighbor's property are always a tricky issue. "In case of emergency." Generally, I advocate "I don't need the neighbor and his property," but the lifting system and maintenance/repair costs definitely cannot be ignored. Has the neighbor already given consent? Conditions?

If the earthworks are not too expensive for this, I would choose the technically simple and maintenance-free solution with the long channel. But then properly with a right of way for the pipeline in the land register. That probably also means that you have to offer the neighbor more than just a case of beer.

It also depends on what kind of property it is and what is already on the planned pipeline route... And how much really goes over the neighboring property. Also to check: over 40m with 2% is 80cm. + 80cm because of frost, that makes 1.6m already. Is the sewer connection still deep enough then (normally yes, but better to check).

Has the neighbor already given the OK? Conditions?

No, I still have to obtain that as well..

The property is only "meadow" and not building land, the owner has long since moved away.. Therefore, I actually see the chance as relatively good..