The shutdown of a septic tank is called "short circuit" in wastewater engineering.
However, some systems can be retrofitted accordingly, and then receive a permit under water law.
Reasons for short-circuiting
From 2015, the EU will only permit small wastewater treatment plants based on biological wastewater treatment processes.
This framework directive for water management aims to protect waters even better from pollutants in the future.
Mechanical forms of wastewater treatment, as is the case with the septic tank, do not have sufficient cleaning performance. The water purified in this way is very high in part and very dangerous for water bodies.
Retrofitting instead of short-circuiting
In some cases, the septic tank can be retrofitted.
A basically better option is the construction of a modern small sewage treatment plant. After all, the septic tank can then continue to serve as a mechanical primary clarification.
Modern three-chamber septic tanks can be retrofitted relatively easily. The costs amount to about 3,500 EUR, depending on the dimensioning and the required cleaning class. For the conversion, there are subsidies between 750 and 1,500 EUR in some countries. Funded is in Bavaria, Thuringia, Saxony and Schleswig-Holstein.
Comprehensive decisions have to be made when constructing a small wastewater treatment plant - especially with regard to the plant type. Here installation and operating costs, but also the required cleaning class play a role in the decision. Careful consideration is definitely advisable here.
While SBR plants are still the most widely used form of small wastewater treatment plants, wetlands are gaining in popularity as a cost effective and highly ecological alternative.
Tips & TricksDo not make hasty decisions and do not be fooled by sales pitches, but rather think about things objectively and in peace and inform yourself sufficiently beforehand. We have put together this comprehensive guide for you too.