Easy to maintain and more economical than a septic tank, phytoepuration is an autonomous and ecological individual wastewater treatment solution.

Particularly suitable for rural areas not connected to the sewer, this treatment process is simple to install, inexpensive and even has the advantage of being aesthetic.

Ideal for a land intended for a Tiny House, self-built or not 🙂

In this article, we explain how phytoepuration works and how to make one yourself.


It is a natural process by plants to filter and clean up wastewater.

Totally ecological and odour-free,phytopuration consists of sanitizing wastewater thanks to bacteria present in the roots of purifying plants (bamboos, reeds, sledges and leaves are the most used).


Nature takes care of everything. It is the bacteria in the roots of plants that will purify the water.

These bacteria are called aerobics, i.e. they need oxygen and do not give off bad odours. They will thus transform organic materials into mineral materials,which can then be assimilated by plants.

In exchange, aquatic plants will provide the oxygen needed for bacteria through their roots.

These plants adapt to all types of soils and different times of the year. This resists both wet periods, i.e. when the dwelling is occupied, and dry periods, when the dwelling is empty.

Another advantage of this sewage treatment system is that there is no odour.

Why? Because, unlike a septic tank which follows the same principle as fermentation in a confined environment without oxygen and where incomplete decomposition generates gases and sludge, phyto purification is based on the same principle as composting. Thus, on contact with the air, the degradation is complete and produces organic matter (humus and water vapour).

It should be noted, however, that at the beginning of the installation of the system by planted filters, the sand will not be invaded by the reeds and may give off slight odors. But these will disappear as soon as the reeds have spread over the entire surface of the filter!

Another question mark about how phytoperutaion works is frost in winter. Again no fear to have! Installed plants are naturally present in water bodies and therefore resistant to frost. In addition, the constant supply of water to the plant purring system limits the formation of frost. Finally, if there is frost, it will only be on the surface because underneath the bacteria will continue to work, create energy and therefore heat.


The 3 steps of phytoepuration

1. Pre-treatment

In the basin, pebbles and reed roots will leave macro-particles on the surface of the water. The other elements will be turned into compost.

2. The treatment of chemical compounds

The purifying plants installed in the basin will suck in nitrates, phosphates and metals. During this2nd stage, the pollutants, which are essentially household, will be broken down.

3. Biological water treatment

Composts stored at plant roots will be “eaten” by bacteria and will be transformed into mineral materials that plants will feed on.


With the exception of a so-called “gardener” maintenance such as mowing, weeding, and cutting reeds once or twice a year, there is nothing to do!

Simply plan every 10 to 15 years to remove the surface layer of compost from the rake, which can be used as a fertilizer for the rest of the garden.

It is thanks in part to this need for low maintenance that the system of water sanitation by planted filters is more economical than a skeptical pit.

Famille de 4 à 5 personnes
Famille de 4 à 5 personnes
Installation costs:About 6000 eurosAbout 4500 euros
Interview:Paying, maximum every 4 years by a professionalFree, gardening once or twice a year.
Installation time:Maximum 20 years if well maintainedAbout 25 years

Also consider learning about zero-rate eco-loans and other aids you may have when installing a plantpuration. Info on Ministry of Ecological and Solidarity Transition .


Install a phytoepuration yourself
Source: Pinterest

The installation of a sanitation system by planted filters can of course be done by a professional but the utilities also allow to install it yourself,following these guidelines:

« […] The municipality (or, in some cases, the community of commune or agglomeration) examines its design by studying the file provided by the owner supplemented by an on-site visit, if necessary. It also verifies its execution on the basis of the screening of the design of the facility and during a site visit made before backfilling. This review is carried out by the Public Non-Collective Sanitation Service (SPANC).

Non-compliant facilities must be subject to compliance within 4 years in the event of a health hazard or proven environmental risk. This period is reduced to 1 year if the building or house is sold.

The owner must maintain his installation regularly (maintenance, draining).

The SPANC verifies the operation and maintenance of the facility at most every 10 years. Check out the wastewater regulations here.

In installation area, plan about 24m2 of plant-clearing ponds for a family of 4/5 people. This natural sanitation system will be built according to the principles of vertical and horizontal filtering:

Vertical filtering by plants:

Wastewater will be transported to the 1st basin where only reedsare planted. Indeed, these plants have the specificity to produce a lot of oxygen and thus allow the development of as many bacteria as possible.

In addition, the movement of these light plants will prevent the waste turned into soil from clogging the gravel filter.
Then, in the last basin, other plants are used for more precise threading.

Horizontal filtering by the layout of the basins:

At the beginning of the routing system, wastewater is filtered through a grid that will allow the most waste to be collected.

In each basin, gravel and sand are increasingly fine are arranged to filter the water horizontally. In addition, a drain is also installed to drain water.

In order for the water to drain naturally, thefirst basin is located high up from the second. Thus, your land must have a vertical drop of more than 1 meter for the installation of the plant purification. If this is not the case, a lift pump will be installed to carry water from one basin to another.

For more technical details on the installation of a phytoepuration, we recommend you consult the magazine La Maison Ecological No. 115 .

In this issue, you will find a step-by-step guide from the Aquatiris design office to self-build its approved phytoepuration capable of treating grey water as well as black water.
Want to learn more about our Tiny Houses? Contact the BIMIFY team 🙂.