Wastewater is the polluted form of water produced from human activities, industrial sewage, domestic sewage, and rainwater. Septic tanks are usually built to collect the sewage and treat it for reuse. They are mostly filled with fecal sludge and industrial waste. The waste is further removed from the fosse septique using a vacuum truck. The vacuum truck has a pump and a tank for transportation. It takes the waste and transfers it to another plant for further treatment. A fosse septique has one or more tanks inside that have a volume of 4000-7500 liters.
Septic tanks are economical and affordable. Septic tanks are necessary to renew the wastewater by natural means and be reused again for our day-to-day activities. It is also easier to fix and diagnose the problems. Septic tanks also have very high longevity and can last up to many years. It is very eco-friendly and does not contaminate the ground water.
Wastewater enters the first chamber of the fosse septique through a pipe and the solid waste is settled down, in the tank. The waste that settles down decomposes through anaerobic digestion. The scum that floats flows into another chamber in the tank where further treatment processes are to take place. Usually, they just need gravity to function, but if transferring to further heights is necessary, a lift pump is used.
Well-functioning septic tanks are odourless. Waste that does not decompose by anaerobic digestion should be transferred from the septic tank as soon as possible. Otherwise, it can lead to overflowing of scum and environmental pollution.
Maintenance of the tanks!
Excessive disposal of cooking oil and grease is difficult to be treated and can cause blockages in the drain. Flushing down of non-biodegradable waste can clog the septic tanks. Paints, bleach, pesticides, etc., can harm the bacteria and other microorganisms present in the tank that is useful for breaking down the waste.
Don’t plant trees around the septic tank because they can go through the tanks causing fissures and leaks. The tree roots further expand due to the nutrient-rich waste, thus further causing complications to the fosse septique.
Excessive wastage of water can overload the septic systems and cause havoc to its working mechanism. Sometimes additives are put into the septic tank for odor control or to improve the breaking down of waste.
Gas emissions from a septic tank
Toxic gases with a pungent stench are sometimes discharged. They are usually hydrogen sulfides formed out of the anaerobic digestion of sulfates. Methane and carbon dioxide are also released due to the fermentation of waste.
In places with a high population and a huge number of septic tanks, there can be groundwater pollution due to a lack of maintenance. If septic tanks do not function properly, the virus and bacteria can seep into nearby water bodies and cause diseases like typhoid, hepatitis A and cholera.