Answers to the most frequent questions.

A septic tank is a holding tank with minimal settling: the wastewater seeps into the ground untreated. A small biological plant treats the water inside the tank before it reaches the ground or a receiving watercourse. Treatment performance is over 90%.

A biological plant works aerobically: the bacteria receive oxygen from a compressor and break down the organic matter completely. No foul-smelling gases are produced. A septic tank works anaerobically, and that is where methane and hydrogen sulphide form. That is the difference in odour.

Biological processes with aeration need an electricity supply for the compressor. Consumption is low. For sites without grid access, there is a special option: the soil filter bed, which works without electricity. We decide which solution suits you best during the consultation.

The requirements depend on the region and the size of the plant. What matters are the regulations of the competent authority and local environmental standards. Together with you and your responsible professional, we determine which permits your project needs. You will find an overview for each country on our country pages.

For delivery we usually allow around two months: about one month of preparation and one month of transport. The site visit is carried out by your installer or a company in your region. The installation itself takes between one and three days depending on the size of the household: the biggest effort is the earthworks.

Usually one maintenance visit a year is enough. During the visit, the maintenance company checks the biological activity, measures oxygen and sludge volume and replaces wear parts. Without maintenance, no biological plant works reliably. With maintenance, it works for decades. Our pilot plant in Chile has confirmed this since 2015.