Property

What should we be looking for in a house with a separate septic tank?

Property Clinic: Is maintenace an issue and what waste-water problems might we face?

Domestic sewage water treatment system in the garden

Wed Mar 20 2019 - 06:00

My wife and I are hoping to buy a house in the next year or two and have attended a few viewings. We have many questions, but one thing we’re completely in the dark about is septic tanks. Is it a good idea to buy a house with a separate septic tank? Is there much maintenance involved? We’ve heard there is strict regulation around them.

Around 500,000 houses in Ireland are served by their own waste-water treatment system. These range from state of the art packaged treatment plants to simple standard septic tanks. The ground conditions into which the treatment system is to be placed determines the most appropriate type of system and also the extent and type of percolation area that is needed. The percolation area is the area downstream of the tank that receives and distributes the initially treated waste and transfers this into the ground. Secondary treatment takes place in the percolation area prior to waste water dissipating into the subsoil.

If you are buying a house in a rural area then you will more than likely be purchasing a home with its own waste-water treatment system. A survey of the property by a professional building inspector will include a visual assessment of the system. This will involve the assessment of location and include the extent of separation from buildings, water courses, wells, roads and boundaries.

The inspection will also typically include the removal of covers on inspection chambers to determine if the system is operating properly. Indications of poor operation include evidence of previous backing up, blockage or poor falls to the drainage pipes. Evidence of poor operation will usually include an offensive odour in the vicinity of the tank due to the absence of a scum layer on top of the waste in the tank.

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The septic tank if operating properly will not generate any significant odour. So, before you commit to buying a property with a septic tank, your building surveyor should be able to give you a good indication that all is in order or indeed the extent of any upgrading that may be required to bring the system into compliance with the 2009 EPA code of practice which deals with systems for single houses.

In terms of upkeep of the waste water treatment system, homeowners have a duty of care under the water services act 2007 to ensure that their system is maintained and operates properly. This means that the septic tank must not cause a risk to human health or cause nuisance through the development of odours. I surveyed a property once where an overflow from a blocked foul waste gully could be seen to seep into the well on the property. As you can imagine I declined the customary cup of tea in the hand.

The 2012 Water Service (Amendment) Act requires homeowners to register their tank with the local authority. So, you should check that the tank has in fact been registered and that the registration fee of €50 has been paid.

Maintenance of all waste-water treatment systems is essential to ensure the correct operation and adequate treatment of waste. With packaged systems, the manufacturer’s guidelines should be followed, to include replacement of any perishable items.

Septic tanks are a little different. The system is basic with no mechanical or electronic parts to be checked and maintained. They require simple desludging and reseeding every 12 months by a registered contractor. A record of this maintenance should be retained to demonstrate compliance if requested by the local authority. Percolation areas can become clogged in time and may need reinstatement.

Septic tanks if designed, constructed and maintained properly should work effectively and should not be a deterrent to buying a property in the countryside. A word of warning, however: lack of oversight during construction in the past and the current opt-out from the requirement to appoint an assigned certifier on one-off houses can mean that issues may be present. It is important therefore to ensure that your chosen building surveyor is familiar with on-site waste water treatment systems.

Noel Larkin, chartered building surveyor and member of the Society of Chartered Surveyors Ireland, scsi.ie

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