Septic Tank Pumping
Prior to the introduction of modern municipal sewerage systems, the world relied on the use of French drains or septic sewer systems. There are still many households in South Africa, not connected to the municipal sewer system that channel solid and liquid waste into underground septic tanks that require occasional cleaning and regular pumping.
The inner workings of Septic Tanks
Septic tanks are designed such that water carries solids via pipes (via gravity or pumps) into the septic tanks. Inside the tank, materials separate and sink in layers to the bottom separated as grease, oils scum and liquids on top. As the tank fills, so the liquid waste and scum overflows out from the tank through porous pipes which then percolates into a specially prepared drain filed located away from the house where it is dispersed. Generally, by the time this water reaches the ground water supply, the water is practically sterile.
Anaerobic bacteria build-up within the septic tank breaks down waste solids, turning it into a sludge reducing the volume in the tank.
Septic tanks which have to be watertight are generally made of concrete, polyethylene or fibreglass and are buried underground away from the household to which it is connected via an inlet pipe through which the household’s waste water is led. Inspection tubes and a manhole cover are generally the only clues as to the location of the septic tank, and these are located such that they allow for easy access for pumping the waste sludge.
Since 1983
Various laws and bylaws dictate how often a sceptic tank is to be inspected and pumped. Generally, septic tanks will need to be pumped every one, two or three years depending on its capacity and load dictated by the number of people in the household. Sophisticated septic systems have a float switches, pumps and various electrical and mechanical components requiring more regular inspections.
Pumping a septic tank refers to the process of removing sludge from the bottom of the tank system which is required to be done before the level of sludge reaches the outlet pipes to the drain field thereby blocking them.
The frequency of which septic tanks are pumped is determined by the following factors:
- The load or size of the household – Obviously the greater the number of people adding waste to the system, the more frequently the septic tank will need to be emptied
- The volume of wastewater that is generated, flowing into the septic tank, the quicker it will fill up requiring the system to be pumped
- The volume of solids entering the system. More toilets and macerators fill up the system more quickly
- Finally the size of the tank combined with all of the above will dictate the frequency at which the tank is emptied. Clearly, larger tanks will require emptying less often.
As a general rule, for a family of 4 people with an installed septic tank capacity of between 4 000 to 5 500 litres, the septic tank will require pumping every 2 to 3 years.
How to pump a septic tank
Due to the various bylaws pertaining to pumping of septic tanks, professional septic tank pumping services should always be engaged
To regularly inspect your system and they will give your advice as to when to have you system pumped. A rule of thumb is that a septic system should be pumped when the scum reaches within 150 – 200mm of the outlet piping system leading to the drain field.
A septic tank pumping services will deploy a tanker truck with powerful vacuum equipment and experienced technicians who then proceed to insert a large hose into the tank through the system’s manhole. The pump will suck out the waste into the tank. The technician will occasionally stir up the muck so as to allow it to be pumped up easier.
How are Septic Tank Pumping Costs Calculated?
Generally septic tank pumping costs are charged by the litre of pumped waste.
What happens to the pumped waste?
Waste is generally transported to specific deposit points dictated by your local authority.
What can I do to maintain my septic tank system?
Homeowners can take a number of precautions to ensure their septic system operates optimally including:
Reduce and limit the amount of water that flows through the system. This can be achieved through the installation of water efficient showerheads, dual flush toilet systems and grey water systems.
Ensure that leaks and drips are promptly repaired.
Reduce solid waste flowing through the system. Ensure that only toilet paper is flushed into the system, avoiding kitchen macerator waste which could quickly overwhelm the system.
Direct rainwater away from the drain field. Downspouts and landscape grading that funnel water onto the septic system’s drain field can interfere with its ability to disperse water from the septic system.
Don’t drain hot tubs into the drain system. This can put undue stress on the septic system; instead, drain water from hot tubs or swimming pools into the yard, away from the drain field.
Avoid putting chemicals down the drain. Chemicals can interfere with the bacterial action that breaks down solid wastes, so avoid flushing them down the drain. This also includes various commercial septic tank additives, which generally do more harm than good. Unless a trusted professional has prescribed such an additive, don’t use any septic tank chemicals.
Rainwater needs to be routed away from the drain field as this could interfere with the septic system’s ability to disperse waste water.
Swimming pool and Jacuzzi or hot tub water should not be drained into the septic tank system or the drain field.
Chemicals should not be thrown into the drain as chemicals will interfere with the aerobic bacterial action that breaks down the solid waste. Commercial septic tank additives can cause harm to the system and should not be used unless prescribed by a specialist.
Following these guidelines will ensure that your septic tank system functions optimally.
If you have any queries or rewire any additional information, please feel free to contact us.