The house is located away from the municipal sewer. The property includes a small sewage treatment plant (Kleinkläranlage). In the sales conversation it is said only that it runs without problems. For your purchase you need more: a comprehensible connection between the existing plant, approval status, operation and future tasks.
This article refers to Upper Austria. It does not provide a nationwide complete presentation of connection and wastewater law or a technical plant assessment for Austria.
First find out which plant actually exists
Request the existing approval, execution and operational documents and have them assigned to the visible plant. Which buildings are served and where is the effluent discharged to? What changes have been made since installation? The technical specialist and the competent authority should clarify any open assignments.
The state information describes small sewage treatment plants as separate wastewater treatment for the non-publicly serviced residential objects explained there and refers to the water law approval. [ABWASSER] An existing plant must therefore not be treated as legally fully clarified solely because of its visible function.
Do not base the purchase on a single maintenance receipt
Arrange existing inspections, maintenance certificates, operational records and known faults by plant and period. Ask which open points have already been dealt with by an operator or the authority. A receipt for the last service appointment can be useful, but does not automatically answer all questions about the current approval and your intended operation.
The state information mentions self-monitoring, examination of the effluent and training for the responsible person as well as electricity, maintenance, repair and sludge disposal costs. [ABWASSER] Have the specific task plan explained on the basis of the decision and the plant. This article does not set its own limit values or inspection intervals for your object.
Fictitious case: More people are a new assumption
A couple intends to live permanently in a house that was previously used only occasionally, together with their family in future. The documents are handed over only as an old folder. The couple initially accepts the assumption that the previous use also proves suitability for the new everyday use.
Before the purchase they have the actual plant, the assumed usage and the future demand examined together. It should be clarified whether changes, evidence or further steps are necessary. The example does not assume any particular required expansion size. It illustrates that a changed usage plan should not be regarded as an already examined operational state.
Include costs and responsibility in the purchase calculation
Request concrete documents about previous operation and an expert assessment of foreseeable next expenses. Separate ongoing tasks from a possible repair or modification. A previous electricity amount is not a complete annual cost forecast.
If several properties use the same plant, it must also be explained how access, tasks and costs are regulated. Do not infer a secured future arrangement from an orally customary handling. Any possible sewer connection issues should also be examined separately with the locally responsible authority.
Prepare a manageable takeover
Before making a binding decision, have it clarified who will take on which tasks after the purchase, which documents and instruction are necessary and which legal or technical points remain open. The sales prospectus is not an instruction manual; such a manual in turn does not replace a confirmed approval situation.
Your outcome can be a sensible purchase with a manageable ongoing task. For this, the wastewater plant must appear in the decision as an installed facility to be continued with costs and responsibility. It should not only appear on the list of supposedly completed accessories after moving in.