Domestic sewage treatment plant ClearFox® Nature – the non electric solution

ClearFox® Nature is a small non electric domestic sewage treatment plant. It is perfect for treating sewage from single houses and small communities up to 32 people. For larger applications of > 50 PE the containerized ClearFox® Nature can be installed. Effluent from the ClearFox® nature is safe for discharge into the environment and can also be used for irrigation. The ClearFox® Nature uses advanced, market leading technology developed in Germany.


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non electric domestic ClearFox Nature

Sustainable and environmentally friendly non electric domestic sewage treatment plant for up to 32 persons

  • Zero energy treatment process
  • No replacement parts ever required
  • Minimal maintenance
  • Simple to install
  • Suitable for off grid / passive house projects
  • Certified to EN12566-3
  • Installed in over 50 countries
  • Fully biological treatment without the need for chemicals
  • Suitable for cleaning grey and black water
  • Below and above ground options available

If you are building a new house or need a septic tank upgrade, then the ClearFox® non electric domestic sewage treatment plant, or the low energy sewage treatment systems we have represent the most robust, reliable and cost efficient solution on the market. Our experts are available to speak to and give advice on how to upgrade your septic tank or how to install a domestic wastewater treatment plant.


The ClearFox® Nature is the best domestic sewage treatment plant to choose if you want a reliable, sustainable and eco friendly solution for your home.

There are many advantages of the CFN compared to any competitor products. These include the following unique selling points:

  • No electricity used to treat wastewater
  • No replacement parts – saving money every year
  • Domestic sewage treatment for up to 50 PE
  • Low maintenance when compared to conventional sewage treatment plants
  • High strength tank reinforced with stainless steel
  • Manufactured from corrosion resistant HDPE
  • Suitable for above or below ground installation
  • Can deal with high and low wastewater flow volumes without issue
  • A flat base for simple installation
  • Manhole extensions for deep installations
  • Simple trouble free operation
  • Certified and approved for over 10 years
  • Certified to EN12566-3
  • Manufactured in Germany under strict quality guidelines
  • Exported to over 50 countries
  • Excellent after sales service

Whether you are a homeowner looking for the best solution for your home, a construction company looking for a reliable system to install on your project, or an agent/distributor looking for a market leading solution – the ClearFox® nature is the system for you.

ClearFox Nature
ClearFox Nature system
ClearFox Nature sewage treatment system


Cleaning is completed in three stages. The raw wastewater is led into the pre-chamber where the wastewater will be settled and buffered. Primary sludge will sink to the tank bottom and will reduce its volume by digestion in the absence of air. On the outlet of the pre-chamber, the water is hydraulically controlled to buffer peak flows. The wastewater is then distributed evenly over the entire day and forwarded to the bioreactor downstream.

Product features:

  • Equalisation of hydraulic peaks
  • Plug and Play
  • Biofilm suitable for underload and overload
  • Biofilter material never needs to be replaced
ClearFox Nature non electric system

The Bioreactor of the non electric domestic sewage treatment plant

The bioreactor consists of a system with aeration elements and media which are arranged above each other in a special order. On the surface of the bioreactor, there is a distribution device which evenly spreads the wastewater over the surface of the media. A flow control device controls the flow from the buffer tank into the biological reactor. This balances peak flows which can cause issues for other sewage systems.

On the fixed media in the biological reactor, bacteria grows and cleans the wastewater naturally. Due to the cascaded plug flow, the water will be entirely cleaned in only one pass through the reactor. At the same time, the secondary sludge is reduced in volume and biologically degraded.

Due to this process technology a further secondary sludge holding tank (such as in conventional biofilm plants) is not required. The special feature of the ClearFox® Nature is that the media never needs to be replaced. This is a unique feature of the ClearFox® Nature system and ensure low cost and reliable operation.

High-performance aeration system

A high-performance aeration system with internal air distribution elements supplies oxygen to the bacteria. Due to the high air circulation, a completely biological degradation is guaranteed. The wastewater filter elements add a mechanical/physical cleaning effect to this biological process.

Many old fashioned systems have air pumps running 24 hours a day mixing air with the wastewater as part of the treatment process. ClearFox® low energy sewage treatment plants have the lowest running costs on the market. This had been independently verified by extended independent tests. If you compare our EN12566-3 certification with any competitor system you will see this. Our systems are EN12566-3 approved for use in Europe. They also meet international requirements.

ClearFox Nature non electric domestic sewage treatment plant

ClearFox® by Breizho

ClearFox® Nature is a small non electric domestic sewage treatment plant manufactured by the PPU in Germany. It doesn’t need any power supply and is the best in eco-efficiency and sustainability. These facts have recently been published in a research report by the Deutsche Bundesstiftung Umwelt DBU.

Nowadays, small wastewater treatment plants are technically state of the art and offer a complete biological treatment of domestic wastewater. So far only technological and economical aspects could help to find the most suitable system. The results of the DBU report “Analysis and evaluation of sustainability and eco-efficiency of small wastewater treatment plants with derivation of product improvements” (1) can now be used to evaluate also sustainability and eco-efficiency.

By 1990 the word “eco-efficiency” was mentioned first and the ecological impact was seriously discussed. Eco-efficiency means to diminish the consumption of resources and the environmental impact as well as to improve the economical benefit. The treatment efficiency is a basic requirement to be reached. All certified German small wastewater treatment systems fulfil that task. The WBCSD (2) has also added to improve the benefit of the product itself and the service.

Within the framework of the DBU research project, the life cycle of a product was followed, which also included the raw material production and the production of the plant. In addition, the operation as well as the disposal and the reuse of the materials were included.

In the case of the procedure according to ISO 14045 (3), the investigation framework was initially established and in this case “small wastewater treatment plant”, was defined. Therefore, on one hand environmental effects including resource utilization must be recorded, and, on the other hand, the product system benefit should be compared with a life cycle cost calculation. The consideration of environmental impacts including the harm categories of human health, ecosystem quality, climate change / greenhouse potential and resources.

Compared to all types of small wastewater treatment plants, the overall environmental impact of biofilters has been shown to be the lowest. BioFilter and ClearFox® nature do not need any electricity! For treatment plants that require electricity, 70-80% of the environmental impacts are generated during operation, and 80% of them are caused by electricity consumption. Therefore:

ClearFox® Nature comes first looking at environmental impacts in the categories of damage

  • Human health,
  • Ecosystem quality,
  • Climate change/ greenhouse potential
  • Resources.

On the basis of these extensive preliminary examinations various indicators for the assessment of the small non electric domestic wastewater treatment plants were worked out. This set of indicators represent the relevant benchmark for the pragmatic assessment of eco-efficiency.


  • Container size
  • Plant weight
  • Net material consumption
  • On-site operation
  • Power consumption in the utilisation phase

The container size has a significant effect on the eco-efficiency. Although larger tanks can have positive effects on the operation, negative environmental impacts and higher overall costs have a far more disadvantageous effect.

The overall cost difference results mainly from the differences in the operational costs. The most cost-effective use is again biofilters, including ClearFox® nature and wetland systems. Over the entire life cycle, the non electric domestic sewage treatment system ClearFox® nature performs even better because no material has to be exchanged during the lifetime, as opposed to biofilters. This is due to the fact that ClearFox® nature does not contain any rotting and clogging materials.

The material types as well as the effort for the extraction and scarcity of the raw materials also flow into considerations. In this context, spare parts must be considered which reduce eco-efficiency, depending on the frequency of replacement and the material. Electrical components in particular must be evaluated negatively.

Non electric domestic system ClearFox® nature also achieves a top score in this category because

  • No electrical components are implemented
  • No filter material must be renewed
  • No spare parts need to be replaced
  • No control is needed

The eco-efficiency indicators show the relationship between the total costs and the environmental impacts. Values > 1 mean higher eco-efficiency. Identical values may well have differences in environmental impact as long as the overall costs are lower. In this respect, for example, an improvement in eco-efficiency by 10% can be achieved by

  • 10% lower overall costs and 10% lower environmental impact (win-win situation)
  • 20% lower costs with the same environmental impact (cost improvement approach)
  • 20% lower environmental impacts at the same costs (environmental improvement approach)

Biofilters and the non electric domestic sewage treatment plant ClearFox® nature as well as wetland systems achieve higher efficiency values than other small treatment plants. However, the disposal of wetland systems has a negative effect.

In summary, ClearFox® nature stand out in eco-efficiency in comparison with other domestic sewage treatment plants. Within the group of biofilters
ClearFox® nature is beneficial due to the lifetime use of the material in the bioreactor.

The DBU- research report proves that non electric domestic ClearFox® nature is leading in eco-efficiency!


  1. Lautenschläger, S. et al. (2016): DBU-Forschungsbericht: Analyse und Bewertung der Nachhaltigkeit und Ökoeffizienz von Kleinkläranlagen mit Ableitung von Produktverbesserungen; Leipzig.
  2. World Business Council for Sustainable Development (WBCSD) (2000): Eco-efficiency: creating more value with less impact, (Zugriff: 17.01.2017).
  3. ISO 14045 (2012): Environmental management – Eco-efficiency assessment of product systems – Principles, requirements and guidelines, International Organization for Standardization (ISO).

Read More about Projects with ClearFox® Nature