wastewater treatment plants
Desludging process for septic tanks and wastewater treatment plants
To ensure your wastewater treatment system is suitable and well maintained, learn more about the desludging process below.
- The desludging process for the Tricel Novo wastewater treatment plant or Tricel Vento septic tank is the responsibility of the homeowner.
- There is the potential danger of falling into the tank during de-sludging when manholes may be opened – take all necessary safety precautions when de-sludging.
- The access cover should never be left off unattended.
- Tricel recommends the use of a licensed company to carry out the desludging process. This should be done with a vacuum tanker. Contact your local county council for a list of the recommended companies.
- The property owner has a legal responsibility to ensure that the system does not cause pollution, a health hazard, or a nuisance.
- It is recommended that the tank should have the capacity to store at least 1 year’s sludge production and be de-sludged once per year.
Does your septic tank or waste water treatment plant need desludging? How to check?
Sludge level in the tank
As the height of sludge/organic solids increase over time in the septic tank / primary settlement chamber (closest to inlet), this reduces the settlement time for solids and the ability of the system to treat the effluent is reduced. A system that is never desludged is at risk of failure i.e. environmental hazard, and causing problems e.g. bad odours.
When to desludge?
- Desludging of the Tricel Vento is recommended on a yearly basis but this depends on tank capacity and use. Best practice is to desludge when the septic tank/primary settlement chamber when half full. It is done to prevent solids rising to the height of the outlet pipe and being carried along with the liquid into the percolation trenches. This, in turn, can block the percolation area and can cause flooding resulting in high costs to rectify.
- For the Tricel Novo wastewater treatment plant, desludging is required when the sludge reaches 50% (or 700mm deep) of the water level in the primary settlement chamber.
Note: in Tricel Novos with a pumped outlet, the pump may have just activated prior to measuring the sludge level. If this has occurred, there will be a lower than normal water level in the tank resulting in an inaccurate sludge level reading. In this case, please measure from the high water line evident on the side of the tank.
How to check the sludge level Tricel Novo wastewater treatment plant?
To check the sludge level in the septic tank/primary settlement chamber, you will require a transparent measuring cylinder with measurement marked the length of the cylinder. Ensure the measuring cylinder is long enough to reach the bottom of the tank without having to bend down into the tank.
We recommend you to book a yearly service during which the sludge level would be checked and advice given whether desludging is needed or not.
- Do not allow machinery/traffic drive over the tank.
- Rolling loads i.e. traffic must not come with in 4m od the tank.
- Static loads i.e. sheds, houses etc must not be within 3m of the tank.
The access for desludging process of septic tanks and wastewater treatment plants
During the desludging process or the septic tank emptying, both chamber 1 and chamber 2 should be emptied.
- The access cover should never be left off while the unit is unattended.
- Desludging process should never be carried out alone.
For the Novo sewage treatment plants, the access for desludging is through the desludging access cover (see below). Note: on large plants, an access cover may also need to be opened. The section of the tank to empty is the primary settlement chamber. This chamber is closest to the inlet and will have no aeration bubbles in the chamber under normal operation. Note that in normal operation there is no need to empty the aeration chamber or the final settlement chamber.
- There is the potential danger of falling into the tank during desludging process when manholes may be opened – take all necessary safety precautions when de-sludging.
- The access cover should never be left off unattended.
No, there is no need to turn the air blower off during the desludging process of the Tricel Novo.
What to do after desludging the Tricel Vento septic tank and Tricel Novo wastewater treatment plant:
Both require filling in after desludging/emptying. The septic tank/primary chamber must be refilled with fresh water after desludging.
In relation, to the wastewater treatment system (Tricel Novo), fill the primary settlement chamber until level with the aeration chamber.
Please note that regular maintenance is also part of looking after your septic tank and sewage treatment plant, check our manuals to see what is the recommended regular and annual maintenance.
How often should you desludge a septic tank or wastewater treatment plant?
Tricel Vento septic tank desludging frequency
For Tricel Vento septic tank, desludging should be carried out yearly to prevent solids rising to the height of the outlet pipe and being carried along with the liquid into the percolation trenches. This blocks the percolation area and can cause flooding. Depending on usage and house population, this period may vary. The minimum recommended desludging period is 1 year for all tank sizes.
Tricel Novo wastewater treatment plant desludging frequency
When the sludge is occupying 50% of the volume of the primary chamber desludging is required, this is when the sludge is 700mm deep. Tricel Novo wastewater treatment plant desludging frequency depends on usage and might be necessary every 1-3 years. The Tricel Novo will require a full service every year to guarantee the efficiency of the plant.
Further information about the desludging process:
Keep records of your septic desludging or wastewater treatment plant desluging.
We recommend that you keep a log along with the receipts from the licensed company. This might come handy to prove that your system has been regularly maintained, in the following situations:
- Inspection from the EPA.
- If you decide to sell your house.
- Moreover, it is required by law to keep records of sludge removal and maintenance for five years.
Desludging process should be done by licensed waste collection companies. Only registered and licensed waste collection companies should be used to desludge your septic tank or wastewater treatment plant. They are insured as well as trained to safely & efficiently handle and dispose of the sludge. They make sure the sludge doesn’t pose any health hazard to the public or cause pollution to the environment.
To find details of a licensed desludging company near you, research online or contact your local authority for a list of contractors. There is the potential danger of falling into the tank during desludging process when manholes may be open – take all necessary safety precautions when desludging.
Farmers with their own land, you can spread their own sludge but only in accordance with the Waste Management (Use of Sewage Sludge in Agriculture) Regulations.
Only competent approved personnel should carry out the desludging process.
Desludging costs vary between counties and suppliers, as a rule of thumb the costs are situated between 200€ and 400€. Make sure to get a waste disposal certificate from wastewater disposal company.
Where does the sludge go? Permitted contractors bring the sludge to authorised facilities for treatment, details of which are available from your local authority.
Different products sold by Tricel
This is a higher treatment standard than the effluent from a septic tank. Please note: all wastewater treatment plants used in Ireland must comply with the EN12566-3 standard and all septic tanks must comply with the EN12566-1 standard.
Tricel Vento: The septic tank from Tricel is manufactured as a primary treatment. Designed for the settlement of your effluent. This product may need an additional treatment like the Sandcel or Puraflo.