Land drainage systems DWA-A 142 with tightness testing

Good evening,

we have received some conditions with our building permit because we are in a Zone 3 water protection area.
With item 2.2.3, we have the requirement for a tightness test... I am somewhat unclear about what exactly is tested, when, where, and up to which point.
Our house builder is making four outlets for wastewater under the floor slab, then we need to find someone who connects these four outlets in a ring and connects it to the transfer shaft.

My questions about this:
How exactly is the test carried out?
Who pays for this? And what does it cost?
From where to where must what be tight?

Regards, Mars

In short, you seal the pipe at the lowest point and fill it with water (completely); after 30 minutes nothing should be missing. The respective construction companies have the necessary knowledge and also create a test report. Only the respective company can tell you the costs. However, this is not so critical in new construction, as you still have access everywhere.

Thank you very much, the approach was correct.

I looked up all the abbreviations and standards once. In plain language:

When commissioning the executing company, it must be ensured that they have the qualification, the material, and that the employees are trained to dig in the water protection area. All buried pipes must meet certain specifications, and finally, a pressure test (about €250) according to DIN EN1610 must be performed.

Regards Markus