Fosse septics and the treatment of waster water generally is a big issue at the moment due to recent rules and regulations which are forcing many home owners to install, upgrade or change their present sewage treatment systems.
There are several pieces of relevant and current legislation that affect domestic properties.
- The first came into effect in January 1992 and stipulated that all household waste water must be processed in the correct manner, by means of a “fosse toutes eaux” (a septic tank that accepts all waste waters) and a filtration system.
- The second came into effect in 2011 when it became a legal requirement to include a “fosse conformity certificate” in the legal package required when selling a house. This certificate, usually issued by SPANC, assesses the conformity of the existing sewage treatment system to prevailing laws and, in noting any defects found, makes both the vendor and potential purchaser aware of any remedial actions that are required.
- Additionally, European Law then introduced the European Standard EN 12566-3 2005 for “Small waste water treatment systems for up to 50 PE (people equivalents)” and, subsequently it was ruled that by the end of 2012 all sewage treatment systems that discharge effluent directly into ditches or watercourses would be illegal, unless they conformed to this standard. The French, not to be outdone by Europe, added an additional criteria to this standard.
The outcome of these new legislations was that every individual sewage treatment system would, at one time or another, be inspected by SPANC to assess its’ conformity to the prevailing laws, and that all sewage treatment systems in France must conform to the French standard NF EN 12566-3+A1.
They are the official body responsible for enforcing that prevailing laws are upheld with regard to the treatment of waste water. Officially known as “Service Public d’Assainissement Non Collectif” they are the only people who can organise a fosse inspection and issue “certificates of conformity” for waste water treatment systems.
They should also be able to conduct soil tests where required, advise on local installers and advise on the best treatment systems available. They are also obliged to advise you on how to remedy any faults their inspections may highlight.
The inspection is to verify if your waster water treatment system conforms to the prevailing laws. Having moved away from being concerned with whether your system presented any environmental or health risk, they are now mainly concerned with compliance and foll a check list of various to be checked during their inspection. When SPANC perform their compliance inspections they will examine various elements including
- Exact location of your current Fosse and Grease Trap
- Access points
- Sludge and scum levels
- Condition of the pipe work
- Filtration system
- Nature of the surrounding soil
- Lay of the land
- Proximity to any water sources, below or above ground
Following the inspection they will either issue a ‘Certificate Of Conformity” or a report outlining any problems and defects.
The systems most likely to fail are
- those that fail to collect all used water as this negates the “Fosse Toutes Eaux” requirement
- systems which cannot be located as they will be deemed as having no system at all (if this is the case speak to neighbours, previous owners anybody as they may be able to help)
- septic tanks without an effective filtration system (make sure that your system is well maintained, de-sludge it or look at replacing your filter matter as this could be cheaper than replacing the whole system) as they are unlikely to met the latest European or French standards for purification.
If your system fails the inspection you will be given 4 years to rectify the problems (this applies to existing property owners, 12 months is given to new property purchasers) and SPANC should guide you regarding the best course of action. We recommend that you research your alternative options thoroughly, speak to a reputable supplier of treatment systems and seek advice from a professional installer. Before purchasing any system get initial approval from SPANC for its installation using the “Demande d’Installation d’un Dispositif d’Assainissement Non Collectif “ available from your local Mairie
You can continue with the sale of your house as long as you have your inspection report and the vendor is well informed regarding any problems. The vendor then takes on responsibility for correcting the defaults and has 1 year in which to do so.
Diagnostic inspectors are sub-contracted by SPANC to conduct the inspections. Their job is to complete the inspection form and pass it to either the Mairie or SPANC.
Fosse Septics, Filter Beds and Micro-stations (12)
There are several options
- a conventional “fosse toutes eaux” with filter bed (sand, natural fibre or reed)
- a compact filter system or
- a micro-stations.
The conventional “fosse toutes eaux” with filter bed works by collecting all waste water in the fosse itself where it is separated and the lighter suspended solids are digested by aerobic bacteria and the heavier sludge waste digested by anaerobic bacteria. As this only results in a reduction of pollutants, some germs and pathogens still remain which could pose a real threat of contamination or disease if released directly into waterways. As such the effluent then needs to pass through a filtration process where the remaining waste and toxic particles are removed before the resulting liquid is either allowed to soak away or be siphoned off .
Proven to be effective in purifying waste water without requiring any electrical input, these systems are ideal for properties that are not inhabited all year round or where the environmental impact is important. However, they do require a sizeable amount of land and can be costly and timely to install. They are also prone to flooding and often require a pumping system to overcome land lie difficulties. As such these systems should not be used where land is limited, where there is a high water table, where the soil is of a water retaining nature or where there is a problematic terrain.
A compact filter system is where the filtering process takes place in an enclosed compact unit. Usually, water enters a “fosse toutes eaux” where it undergoes pre-treatment through separation and anaerobic and aerobic digestion. The water is then passed using a gravity led system over a series of filtering layers where the water is clarified to an acceptable level.
As these filter systems are compact and enclosed, both the space required and the chances of flooding are significantly reduced. However, as they still rely on a downward movement of water they remain unsuitable for very problematic terrains and will often require a pumping system to ensure the effective movement of water into, or out of, the system.
Micro-stations compact units that collect and treat used water without the need for a large filter bed. These units are made up of numerous chambers, basically a settlement chamber for waste separation and bacterial pre-treatment, an aeration chamber where the remaining liquid effluent undergoes enhanced biologically treatment and a clarification chamber which removes any remaining fine solids before the effluent can be discharged.
Micro-stations tend to be quick, easy and cheap to install and the minimal space required makes them ideal for properties with little land or where disruption to existing gardens needs to be kept to a minimum. However, as they rely on an electrical input to run the compressor, they are unsuitable for holiday or secondary homes and, as they vary in size and depth, the presence of bedrock may make their installation financially non-viable.
A “fosse toutes eaux” is simply a fosse that collects all waste water from a property. This includes bathroom, kitchen and utility room waste water. It does not include rainwater.
De-Sludging needs to be undertaken on all systems with any sort of “fosse toutes eaux” and/or settlement chamber. The frequency of de-sludge depends on the system and on the number of people using the system. Official recommendations are to de-sludge conventional fosses when 50% and for microstations when the settlement chamber is 30% full. Only a licensed waste collector should carry out the de-sludging process.
Anaerobic digestion is a series of processes in which microorganisms break down biodegradable material in the absence of oxygen. It is through this process that solid matter which falls to the bottom of the fosse is broken down.
Aerobic digestion is the process of oxidizing and decomposing the organic part of the sludge by micro-organisms in the presence of oxygen. In aerobic wastewater treatment systems, micro-organisms feed on organic materials to stabilize them, and reduce biological oxygen demand and suspended solids in the wastewater. Since oxygen needs to be present the process can be accelerated by introducing further air movement. In this way the compressor used in micro-stations can speed up significantly the breakdown of effluent in water.
The clarifeid water from the micro-station may be discharged into a road drain, a ditch, and (with the correct permission) watercourses such as a river, stream or lake. Because the effluent is so highly oxygenated, it can actually improve the oxygen quality of the receiving watercourse.
Replacing And Upgrading Your Waste Water Treatment System (8)
Always speak to SPANC before any remedial action is taken. Find out why your system failed and what you need to do to resolve the issues. With some idea of why your system failed and an idea of the solution find a recognised sewage treatment system installer. Look under “assainissement” in the yellow pages, search the internet or ask SPANC for recommendations. Where possible get the advice off at least three installers and speak to their previous clients.
Together you should then discuss options, research the alternatives on-line and choose your preferred system. Make sure that your system choice is on the official SPANC listing which your installer should know about, and before purchasing any system obtain initial approval from SPANC. Having received approval obtain a quote or “devis” your from installer, detailing all the works and materials required. There should be a French version of this and it should state a start date for the works. The devis should also have your installers work reference (a SIRET, SARL number). The installer should help with all the paperwork necessary to obtain approval and your “Certificate Of Conformity”.
In most cases you will need to complete an application form “Demande d’Installation d’un Dispositif d’Assainissement Non Collectif” which can be obtained from your local Mairie. This will require a soil test and land survey to be undertaken and a plan of where your system will go marking any water courses, ditches, trees or obstructions etc. This is then sent to SPANC prior to installation for their initial approval.
A percolation test is a simple test to measure the suitability of your land for your preferred system. Although it is largely irrelevant for compact filter systems and micro-stations it is still required on the approval form.
Either your installer of SPANC officer can conduct the test although both may charge. Alternatively you can perform the test yourselves. Firstly dig a hole 30cmx30cmx50cm deep. Dig this hole where you are likely to put your fosse or micro-station but make sure the hole is at least 3m away from any tree or well. Secondly, fill the hole with water and leave until the water has disappeared. Finally, put 10 litres of water in the hole and time how long it takes to disappear.
Whilst digging the hole check if the soil is rock (rocheuse), gravel (caillouteuse), sand (sableuse) or clay (argileuse) as they also want this information.
You can find installers either by looking under “assainissement” in the yellow pages, asking SPANC for recommendations or searching the Internet for fosse or micro-station installers. If possible get at least three individual quotes, speak to their previous clients and ask the installer plenty of questions. When obtaining the quote it should detail all the works and materials required, there should be a French version and there should be a start date for the works. The devis should also have your installers work reference (a SIRET, SARL number).
Search the internet for the best prices and make sure you or your installer contact them direct asking questions about their products, their payment process and delivery service and their warranties. Make sure the supplier has a French land line contact number, and ensure that either you or your supplier gets to speak to a real person who sounds knowledgeable on the subject. Also ensure that you get a quote for the supply of the system and that you know if taxes or delivery charges are included or not.
No, in France any approved micro-system needs to have had several evaluations and been approved by the Ministry of Health of having complied with both the European standard EN 12566-3 but also the more stringent French additional criteria NF EN 12566-3+A1. They will then be given an agreement number (the numero d’agrément). Only systems with this agreement number will be approved by SPANC.
Although we recommend systems be installed by a registered installer, you can install them yourself using the technical manual supplied. You will need to arrange with SPANC what inspections they will require and when throughout the process.
Under the principal of freedom of commerce and industry, SPANC cannot in any way affect individuals in choice of a company.