Living With the Fosse Septic

I remember those halcyon days in the UK when flushing the toilet meant that you would never see your bodily waste again. In rural France, unfortunately this cannot be guaranteed and you spend a lot of your spare time making sure that your fosse septic (septic tank) is functioning correctly in order to ensure that the required bacterial action continues.

 Actually it is a marvellous system which deals with all your household liquid waste and if correctly installed, ensures that no environmental damage is caused by the eventual run off.

 Since 1992 the French government has taken its environmental responsibilities seriously and started to enforce European directives on the disposal of waste. An organisation called SPANC, (Service Public d’Assainissement Non Collectif,) has the responsibility of inspecting and enforcing the safe disposal of liquid waste. An initial site visit is carried out to ensure that those properties that cannot be connected to a communal or town drainage system have a safe system of collection and treatment.

 It has caused considerable rebellion amongst some rural Bretons who challenge the need for change and consider the costs of bringing old systems up to the required standard prohibitive. In reality the standard of some waste systems is a cause for real concern and the risk of harmful pathogens entering the water system a major concern.

 Before agreeing to purchase a property, ensure that the estate agent provides you with evidence that the water treatment system has been inspected and certificate of conformity issued. If the system is unsatisfactory, remedial work can be expensive and sometimes difficult to resolve if outside space is at a premium.

 I should warn you that this subject is often a favourite for discussion at dinner with the rural French! So you can really impress the neighbours if you understand the basics.

 All you water waste with the exception of your roof runoff, should be directed into a storage tank usually buried below ground. Water from kitchen sinks which may contain fat residue must go via an interceptor which prevents the fat from blocking pipe work. The one exception to this is if the tank entry is no more than 10 metre from the sink outlet, in this case an interceptor may not be required.

 The actual fosse (tank) is separated into two chambers, one for the entry and solids and the second for the treated water and runoff outlet. Both tanks have access lids to enable inspection and eventual emptying and cleaning. From the tank pipe work takes the waste water which has been biologically treated to a run off grid buried beneath your lawn. The run off grid is a system of perforated pipe work surrounded in special gravel which allows for the gradual absorption of liquid into the surrounding soil.

 The size of the Fosse Septic is dependant on the size of the house but is usually between 3-5000 litres in capacity.

 Maintaining the correct function of the fosse is simply a matter of adding a biological activator such as ‘eparcyl’, at prescribed intervals, usually monthly to the toilet and flushing. The substance enters the tank and reactivates the biological process.

 The tank should work happily without physical intervention, but should be emptied at least every 4 years by a licensed waste removal contractor. It is not acceptable for the local farmer to pump out the tank and spread it on his land.

 This is a very basic description of the fosse system and I would recommend you consult, http://www.spanc.fr/page.php for details of the requirements and inspection process.