French Septic Tanks, Fosses Septiques, and Sewage Treatment Systems.

France’s public sanitation service (service public d’assainissement) is maintained by the commune and overseen by two government service entities: SPAC (for collective sanitation systems, i.e. those connected to the mains sewer system) and SPANC (for non-collective sanitation systems, i.e. individual systems installed on domestic or business properties).

If your property is located in an urban area or close to a large country town, there is a good chance you will be connected to the mains sewer system. In this case, your sewage and waste-water management will be taken care of by your commune’s water supplier or syndicat d’eau (water syndicate), and the applicable costs will be added to your water bill. Read more about this in our article French Water Supply and Drainage.

If however, you are not in an area with connection to the mains sewerage system, your property must have a fosse septique (septic tank) or non-collective sewage treatment system in order to manage your wastewater and sewage. Some 5 million rural properties throughout France have non-collective sewage treatment systems in place and there are strict rules and regulations in place to ensure that they comply with EU standards.

The first thing to note is that it is a legal requirement of all homeowners to install and maintain a fosse septique or sewage treatment system if your French property isn’t connected to the mains sewer system.

In 2012, a new ministerial decree came into force governing the standards of non-collective sanitation systems, and since then, many French homeowners have found themselves having to upgrade or replace their old or malfunctioning fosse septiques to ensure they meet with current regulations.

Read more about your legal obligations for individual sewage treatment in France.

Fosse Septique or Sewage Treatment System?

A septic tank or fosse septique is designed to filter and treat your household sewage and wastewater. All waste from your kitchen, toilets, and bathroom will be directed into the tank, which will typically be buried in your garden. The sewage system is designed to filter and pre-treat the waste-water, transforming it into gas, carbon dioxide, and water, and removing any toxic particiles, before draining the water into the ground without causing damage to the environement.

There are number of sewage treatment systems available and which one you choose will depend upon your budget (both short and long-term), available space, and household needs (a holiday home left empty for long periods may require a different system to a busy primary residence, for example).

Traditional sewage systems or fosse septiques remain popular, but it’s important to consider their long-term maintenance – sand filteration needs to be replaced each 10 to 20 years, and the expense of doing this could be as high as €10,000. Compact filters are a good choice where space is limited and they are one of the more economical and eco-friendly options as they don’t need electricity to run. Reed bed and dry toilet systems provide ecologically friendly options, although they are comparatively high maintenance. There are also a number of ‘microstations’ available, which are purpose-designed to be compact, ecological and easy-to-maintain.

Read our article on Types of Sewage Treatment Systems in France.

Installing or Upgrading Your Sewage Treatment System

Installing or replacing your sewage treatment system requires a hefty financial outlay — expect prices to start around €5,000 and the costs of installation may end up being much more depending on the system you choose. It’s important to not only consider the short-term outlay but the long-term costs too. Upgrading your septic tank with an approved sewage treatment plant might be a big expense, but it is very likely to save you money in the long-run.

To find out more about installing or upgrading your sewage treatment system, read our Step-by-Step Guide and follow our Sewage Treatment Upgrade Checklist. You might also want to investigate the different grants and subsidies available for homeowners installing a sewage treatment system.

If you are buying or selling a property in France, there are a number of Diagnostic Surveys, known as a Dossier de Diagnostic Technique or DDT that are legally required to be carried out on the property. The seller is responsible for carrying out these surveys (and paying the associated fees) and among them is a report on Waste Water Drainage (Assainissement Non Collectif) carried out by SPANC.

You can read all about these surveys, as well as what to do if your sewage treatment system doesn’t meet the legal requirements in our article Mandatory Diagnoses When Buying a House in France.

Maintaining and Servicing Your Sewage Treatment System

Your septic tank or sewage treatment system is subject to inspections a minimum of every 10 years (typically every four years) carried out by SPANC and if your inspection report (avis de contrôle) shows defects or violations of protocol, you will have up to four years to carry out the necessary work to bring your system within the legal guidelines.

Read more about this in our article on SPANC inspections.

Tips for Maintaining Your Sewage Treatment System

Another important consideration for properties with non-collective sewage treatment systems is your day-to-day habits. You should be given clear guidelines for maintaining your system by the manufacturer, but some general rules to follow include:

• Be careful over the amount of toilet paper you use and what gets flushed down your toilet. Septic tanks do not deal well with solid waste (such as sanitary products, for example) so you shouldn’t flush anything other than toilet paper. You should also avoid pouring oil or greasy products down your kitchen sink.
• With this in mind, consider purchasing sink trappers to avoid food waste, hair, or other solid waste going down your plugholes. You should also install lint filters on your washing machine outlet.
• Always use cleaning products that are deemed safe for septic tank use – these are usually clearly labelled with ‘pour fosse septique’.
• Use biodegradable shower products (shampoos, etc) and never flush medicines or anything chemical. These can interfere with the system and upset the bacterial balance in your tank.

Our Essential Reading articles cover everything you need to know as a French homeowner from property taxes and home insurance to paying your bills. Perhaps you also need recommendations on removals to France, advice on building and renovations, or tips for managing a second home? FrenchEntrée is here to help! We can even advise on selling your French property.