- What is a septic tank?
- The different septic tanks
- On the side of legislation
- How to maintain a septic tank?
- What are the advantages and disadvantages?
While fourteen million users are not connected to public networks, the septic tank is the most widespread individual evacuation system in our area. With the exponential growth of our water consumption, the evacuation is becoming a crucial point in the French habitat. Operation, legislation, price or maintenance this week, HandymanDuanche tells you everything about septic tanks.
What is a septic tank?
A key element of a purification system, the septic tank ensures the partial liquefaction of pollutants concentrated in domestic wastewater. It thus prevents the passage of raw water in the drainage and purification devices. In concrete or plastic, this tank consists of two compartments. In the first, the waters ferment through their organic matter, producing carbon dioxide, hydrogen sulphide and methane. During this step, called digestion, the solids fall to the bottom of the tank to let only light materials. They then arrive as effluents in the second compartment before coming out pre-treated and stabilized. These effluents are then directly discharged by a trench drain dug deep or reprocessed in various filters to purify.
The different septic tanks
Septic tanks "all waters", used in the absence of any sewer, receive all of the wastewater of the home (black water and greywater). "Classic" septic tanks receive only black water (sanitary water). As a result, they are equipped with a "grease box" to eliminate large amounts of waste and retain fat. The choice of a septic tank is therefore based on the initial installation of the house.
On the side of legislation
More and more controlled and regulated, septic tanks must respect French and European standards. The dimensions of the tank are thus strictly defined according to the size of the house. Also note that direct discharge of septic tank water into a well or sewer is strictly prohibited for pollution reasons. If 50% of current facilities are non-compliant, the state is doing everything it can to fix it and home inspections are increasing. Since 1997, the law provides for the visit of an expert every four years minimum, flexible depending on local communities. In the event of a malfunction, the owner of the premises must remedy the problem, and will be held solely responsible for the pollution generated.
How to maintain a septic tank?
A serious and regular maintenance of your pit will ensure its longevity and its good functioning. It is imperative to have it flushed on average every four years or every two years for all-water models. From time to time, check the flow of the effluents and clean the filter elements twice a year without forgetting to empty the grease trap as soon as it fills up too much. Also make sure that the look of the pit is perfectly accessible.
What are the advantages and disadvantages?
If septic tanks (from 5000 Euros) seem to be more economical than the connection to the collective network, they are not more ecological. The effluents, straight out of the tank, are often released directly into the environment, thus causing health problems and polluting the groundwater. In addition, the tank requires a large amount of water to chase waste that clutter.
The septic tank, practical certainly, but not ecological! However, be aware that there are alternatives that are more economical and more respectful of the environment, such as phyto-purification or individual micro-treatment plants.