Septic tanks are widely used for on site sewage treatment for domestic homes which are not connected to the sewer system. Little attention is given to the septic tank until there are problems such as smells or poor drainage or ponding on the surface. A little maintenance of the septic tank can be very helpful in maintaining performance of the septic tank. The outflow from a septic tank percolates through the soil. If it is not adequately treated it can cause problems due to contamination of groundwater which may be a source of drinking water for other people in your community. The activity in a septic tank is biological in nature so regular microbial maintenance is very beneficial and saves a lot of money in the long run.
In the current debate on the subject of registration and inspection of septic tanks one topic which has not been addressed is maintenance. The normal attitude is that the septic tank is down at the bottom of the garden or in the next field and is out of sight and out of mind. Nothing is ever done until there is a problem with the septic tank such as slow flow, sewers backing up or surface ponding. At that stage emergency response is required and that is expensive. A little preventative maintenance goes a long way to ensuring the septic tank is working effectively and producing a reasonable quality final effluent. After all, this treated wastewater is being discharged back into the environment. So with poor treatment there is the possibility of contaminating groundwater which may be a source of drinking water for your neighbours or community.
Over time due to non-biodegradable solids and slow degradation of solids in the septic tank the sludge layer at the bottom builds up. This sludge build up means that the volume of the septic tank available for treatment is significantly reduced. This results in the outflow from the septic tank to the percolation area having more solids and will ultimately lead to blockages to the soakaway or percolation area. The septic tank should be pumped out every two years. During the pumpout the inlet and outlet pipes should be checked. Leave a little of the sludge (up to 10%) in order to seed up the system again. Make sure the water level in the tank is brought up above the inlet and outlet T-pipes (this prevents solids and fats getting into the soakaway).
Many of the common cleaning products used in the home contain bleach, sanitisers, detergents, etc. and these can have a detrimental effect on the microbial life in the septic tank. Current guidance from EPA is that dishwashers and washing machines should also flow to the septic tank. Poor biological activity will result in little solids degradation and very poor treatment in the septic tank. This leads to higher levels of solids and emulsified grease entering the soakaway where it will ultimately lead to blockages. It is very important that the biological activity in the septic tank be maintained. Regular dosing of microbes to the septic tank is very important and can also be used for maintenance of the soakaway. The product can be dosed to the manhole at the start of the soakaway.
Old wives tales such as throwing a dead chicken or cat into the septic tank is not the solution! There are specially formulated products such as Septa Clean available which quickly restore microbial activity in the system. Regular dosing will help to maintain biological activity. After the septic tank has been desludged it is very important to dose it to ensure performance is quickly restored. Also if the septic tank hasn’t been used for more than a week due to holidays a top up dose will be very helpful.
Septic tanks which are adequately sized, located and regularly maintained by pumpouts and dosing will be much less likely to be inspected. In fact the EPA on their web site make the following comment in relation to risk based inspections “It means that if your Septic tank or domestic wastewater treatment system is properly installed and maintained you are unlikely to undergo an inspection.”
The key parts of the inspection of septic tanks which is a visual process are:-
- Making sure the septic tank is not leaking.
- Making sure the soakaway is not blocked – slow flow, ponding on the surface, etc.
- Septic tank is regularly pumped out (every 1 – 2 years or as required) – need to use a registered contractor and keep records of pumpouts.
- Absence of bad smells. A bad smell is an indication that the microbial activity in the septic tank is not good and the system will be giving poor treatment.
- Surface water from gutters, storm drains, paved areas, etc. does not go to the septic tank but to a separate soakaway.
For more information on septic tanks contact us.