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What autonomous sanitation in new construction?

Wastewater from the new house must be treated.

Table of contents

A autonomous sanitation solution is essential if your the land is not connected to the sewer? Objective, treat your wastewater yourself. phyto-purification, septic tank, micro-station…, How to choose ? Is it effective? What are the best practices and regulations? We take stock.


What is autonomous sanitation?

when house to build is not served by a public network wastewater collection, owners must put in place a individual wastewater treatment system. The latter prevents health risks, protects our water tables and limits the impact on the environment of your future home. In France, 15 to 20% of houses have a non-collective sanitation system or ANC.

To go further read the article ” Adapt your House to your Building Land "

Septic tank – all-water tank the traditional solution

All of this individual sanitation solutions represent around 65% of the market. But today we no longer talk about septic tank, but from an all-water pit. The difference is that the first is only used for the treatment of sewage (water coming from the toilets), when the septic tank recovers all so-called gray water (household wastewater coming from the kitchen, bathroom, laundry room, and toilets).

Buried sanitation – Septic tank or other how does it work?

THEsanitation not connected includes two steps:
– The pretreatment consists of an all-water pit, a watertight tank which receives all the wastewater from the house. It retains solid materials, floating waste and liquefies polluting materials. It can be supplemented by a pre-filter and/or a degreaser tank.
– Treatment: The soil in place generally ensures thewater sanitation thanks to naturally present bacteria. But if its nature is not suitable, we will use a reconstituted soil (sand filter, zeolite bed, etc.).

Micro-stations, the solution for small plots

These devices use the principle of aerobic degradation of pollution by microorganisms in culture
fixed. This space-saving system is particularly recommended for small lots and does not require major work for its installation. More expensive in the long term, micro-stations require energy to operate. Furthermore, they cannot withstand prolonged periods of non-use.

It is possible to treat wastewater from the house with plants and reeds.
Phytopurification: an effective natural ecological autonomous sanitation that beautifies the garden of new construction. Aquatiris.

Phytopurification, the ecological alternative

In recent years, many owners have chosen to make their autonomous sanitation landscaping. The wastewater travels in the open air along a filter planted with reeds and other flowering plants. Their roots and the substrate create an environment favorable to biological activity and the development of purifying microorganisms. The materials are automatically degraded. The whole thing is odorless, requires very little maintenance and beautifies the garden!

Septic tank or other Individual sanitation system, what legal obligations?

Before any work, you must:
– Have a soil study to determine the appropriate system.
– Have your project validated with the SPANC Public Non-Collective Sanitation Service.
– The certificate of conformity for your non-collective sanitation project, issued by the SPANC will be attached to permission.
Your constructor Sic houses will help you in all these steps, as well as in choosing the installation best suited to your project.

What place for non-collective sanitation?

You must take into account the need for sanitation as soon as you build your house. Indeed, this type of installation cannot be placed just anywhere. Certain distances must be respected both from the home and from your neighbors' plots. It must also be located at minimum distances from trees on your land and be at least 35 meters away from private wells or water catchments intended for human consumption.

Autonomous sanitation installation
Recommended distances for the installation of non-collective sanitation on land- Information guide for users of non-collective sanitation – September 2012


How to size the installation?

The size of a individual wastewater treatment plant depends on the number of inhabitants. In new construction, we thus rely on the number of main parts of the house to build. It is then necessary to take into account the occupancy time of the house because certain installations require regular contributions to function correctly and are therefore not suitable for second homes.
In addition, it is necessary to take into account the land constraints such as the nature of the soil, a water table close to the ground surface, a plot in a flood zone, a zero or excessive slope, because all these elements contribute to the choice of this or that device.

To find out more, discover the ” 10 questions to ask yourself when choosing the right building plot for your house "

Can we always install autonomous sanitation in new construction?

There are sometimes specific local provisions on the disposal of treated wastewater. Indeed, certain territories may be more sensitive to pollution. The installation of certain devices Wastewater nearby could thus directly affect certain activities: drinking water supply, swimming, shellfish farming, fishing on foot, etc.

Septic tank, what maintenance and best practices?

Whatever the sanitation solution chosen, it will not be able to clean up certain products that we tend to throw into our sinks or toilets. Paints, solvents, products whose labeling indicates toxicity, pesticides, but also frying and draining oils and greases will not be treated and may harm the operation of the installation over time. Objects that are difficult to degrade such as cigarette butts, feminine protection, condoms and wipes should also be avoided.


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