Waste water and sewage treatment in France

LIKE everywhere in Europe, used waste water cannot be discharged in France without appropriate treatment either via a private waste water treatment system or a municipal waste water plant, writes Keith Lacey.

There are two main types of water treatment plants:

– Assainissement Non Collectif (ANC) that are all privately owned waste water treatment plants whatever the size, from an individual house septic tank or a 200 bedroom hotel waste water treatment plant.

– Assainissement Collectif which are all municipal waste water treatment plants no matter the size.

Any French township of more than 2,000 inhabitants has an obligation to have a municipal waste water treatment plant. Below that number, it is a choice.

Many small villages will remain with only a small municipal plant for the village centre and the remainder will be private systems. Some villages cannot afford a municipal plant so everybody has to have a private system.

All in all, this means that France has more than five million private waste water treatment systems.

French regulations, role of Mairies and SPANCs

Knowing the above, the French government has two technical regulations, arrêtés, describing:

– All waste water systems up to 20 Population Equivalents (PE) Arrêté du 7 Septembre 2009

– All waste water systems above 20 PE Arrêté du 22 Juin 2007.

These regulations are based on the size of the system whether privately or municipally owned.

Administratively, the Maire is responsible of the good applications of the above mentioned regulations on his municipality. This is of course difficult for the small municipalities as they have very few means.

Because of this the government created the SPANCs (Service Publics d’Assainissement Non Collectif) and SATESE (Service Assistance Technique à l’Exploitation des Stations d’Epuration).

The role of these organisations is to be a technical and legal adviser to the municipalities for the private and municipal waste water plants.

Regulation for waste water systems up to 20 Population Equivalents (PE) Arrêté du 7 Septembre 2009

The vast majority of the private systems are for private homes and fall into this regulation.

The owner is responsible for having a good functioning waste water system and if this is not the case (the SPANC are supposed to have controlled all existing systems by end 2012), the system has to be renewed.

Technically the owner will have a choice between

– Septic tank + drainage pipes, sand filter or a zeolite filter

– Package waste water treatment which has a government agreement

The choice will largely depend on the size of the project, available space, type of soil, type of use, geographical locations and other factors.

A good choice is not that simple and in many cases the owner will request an etude, or call on the services of a consulting engineer or a contractor to offer advice on the best choice.

The project having been put on paper then has to be submitted to the local SPANC via the Mairie. The SPANC cannot impose any system but it is their role to say if the proposed system is properly sized and conforming to the above mentioned regulation.

They will give their answer via the municipality who will then give the green light for realising the assainissement non collectif.

Once finished or in some cases as is normal, during the work, the SPANC will request to come and visit to inspect, after which the happy owner will be able to receive a certificate de conformité for their installation.

All this is not free and the controls are to be paid by the owner to the SPANC.

Following that, the SPANC is supposed to oversee installations with a minimum of one inspection visit every eight years to see that the private installation is properly maintained and it is functioning as it should do.

The investment of a private waste water installation is entirely at the charge of the owner but they can have a zero per cent interest loan (eco prêt à taux 0) if the system installed has no electricity.

The regulation for waste water systems above 20 PE Arrêté du 22 Juin 2007.

In these sizes a proper study/design has to be done to justify the sizing of the waste water treatment. Also the required purification performance will depend on the local situation.

The owner/engineer is free to choose the treatment process so long as it guarantees the quality of the treated effluent which will have to be regularly measured (usually once a year) by the owner.

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