Non-collective sewage treatment

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More than 98% of Vannes' homes are now connected to the collective sewage network, which represents more than 31,645 water service customers in all.

Approximately 467 dwellings in Vannes still have autonomous sewage systems.In the main, these are houses located in peripheral areas (Meucon, Tréhuinec, Le Vincin, etc.) whose connection to the public network cannot be carried out for technical, financial or topographical reasons.

Having your non-collective sewage system checked:Why?, How?:
These dwellings, which cannot take advantage of what was once known as the "tout-à-l’égout" (main drains) must nevertheless provide a guarantee of the perfect operation of their autonomous sewage system.In other words, existing installations such as septic tanks or combined water tanks must of course be in perfect working order.
Consequently, they must meet the requirements of standards guaranteeing the protection of environmental quality, in particular that of surface water (streams, lakes and ponds, rivers, etc.) and ground water.

In accordance with the Code général des collectivités territoriales (code of practise of territorial communities), councils are now obliged to "bear the cost of inspecting non-collective sewage systems".

In other words, all autonomous sewage facilities, planned or in operation, must be checked by the town council.These obligations, laid down in the Water Law of 3 January 1992, are comparable with the compulsory MOT test for vehicles.

They are the responsibility of the public non-collective sewage treatment service (SPANC) that has been fulfilling its duties since the 1st January 2006 and that is covered by special regulations.


If the area where you have planned to build is not covered by the town's collective sewage network, you must follow the following steps:

1- Obtain information in the town hall (Planning department)

  •  Consult planning documents (POS – land use plan, PLU – local urbanisation plan) and sewage area plan
  • In parallel with your planning application (planning permission, work authorisation, planning certificate), prepare an application for a non-collective sewage system based on a soil survey report drawn up by a specialist engineering agency.

An application form allowing you to give details of the design of your project for checking purposes is available in the town hall or can be downloaded below.

2- Permission for your Non-collective sewage system project

  •  Hand in your soil survey at the town hall, together with your application form containing all the information provided by the engineering agency and your planning application (planning permission, work authorisation) if necessary.
  • Your application will be sent to Vannes council's public non-collective sewage service (SPANC) at the Direction de l'eau et de l'assainissement (water and sewage management service) for the design to be checked.

A decision will then be given on your project.

Note:If you have only an application for a non-collective sewage system to make (without a planning application), you can hand in your soil survey and your information sheet at Vannes council's public non-collective sewage service (SPANC) at the Direction de l'eau et de l'assainissement (water and sewage management service)

3- Works

- Contact a contractor and give him a copy of your soil survey and the reasoned decision from the town hall.

    - When the non-collective sewage system has been installed but before the treatment system has been filled in with hard core and enclosed, you must contact SPANC at least one week in advance so that a construction check can be carried out.

Our technician will check if the system put in place complies with the design for which permission has been given and if the work has been carried out in accordance with good trade practice.

A decision on the construction of your system will be issued:

  • If the decision is favourable your will receive a statement in duplicate certifying that the work has been carried out properly, one copy of which must be signed and returned.
  • If the opinion is not favourable, the changes notified in the statement will have to be made.

4- Operation and maintenance

You are responsible for the correct operation and maintenance of your non-collective sewage system.

Approximately every four years, depending on the type of system, SPANC will carry out an operation check of the system and will check that the combined water tank is draining properly.

You will asked to provide statements proving how the waste material is disposed of when the system is emptied

Note:The installation of a non-collective sewage system is an integral part of a dwelling and must be installed on land where building is permitted.


The first time we visit the site, an evaluation of your system will be carried out by our technician; a statement of the condition of your  system will be issued, together with instructions for any steps that must be taken.

The operation check will subsequently be carried out approximately every four years by our technician.

For further details:Vannes town hall

Direction de l'eau et de l'assainissement,
7 rue Joseph le Brix.
Phone : +33 (0)2 97 01 63 50

A technician from the water and sewage management service is at your service and will provide advice on maintenance or improvements in compliance with the "Environmental quality in Morbihan" charter drawn up by the Conseil Général (county council), that Vannes town council has signed up to.



Place Maurice Marchais

Tél. : 02 97 01 60 00



Monday to Friday from 8h to 12h15 and from 13h15 to 18h.Saturday morning from 9h to 12h.



7 rue Joseph Le Brix

Tél. : 02 97 01 60 00


Ouverture :


Monday to Friday from 8h15 to 12h15 and from 13h15 to 17h.


Permanence of the state civil service, Saturday 9am to 12pm.Are given priority: the declarations of birth and death as well as passport applications (by appointment).


Saturday morning, home phone from 9h to 12h.