[chrismahon]

We had a system inspection a few days ago. Seems everyone is being checked to make sure they have complied with the statutory requirements that they were informed of after the first inspection 8 years ago. Failure to comply means a complete replacement of your system, even if only part doesn't comply. At the moment that costs between €12,000 and €15,000. To say I was a bit worried was an understatement, because ours had failed on the lack of an above roof air vent. Fitting one would be a near impossible task because all waste pipes are glued together- there are no fittings with seals. The wall is made of soft stone with clay/mud binder, so fixing anything to it isn't going to last long. Turns out we don't need a vent because our system doesn't smell and as a result our system is fully compliant.


The very nice lad doing the inspection (who spoke perfect English having spent 3 years at Manchester Uni) went on to explain the maintenance requirements. Dip the first tank regularly with a stick and have it emptied when half full. Tried that and our solid sludge won't stick to the stick, so I can't tell where it is apart from a change in resistance as the stick is pushed in- bit less than half full I think? In the second chamber there is a tray full of volcanic rocks. These are there to attract any solids which then stick to the stones rather than going into the soak-aways and blocking them. The tray needs to be removed every year and the stones hosed clean. To my knowledge that has never been done, which is why the stones or tray can't be seen. He did recommend that I didn't put my bare hands into the fluid to pull out the tray which has rope handles- as if I needed telling. I have ordered some long gloves.


The purpose of posting on this subject again is because I asked him about emptying the tank by aeration and the answer is very important- DON'T!!! The reason is simple. The microbes in this type of tank live without oxygen whilst breaking down the waste. Adding oxygen will just kill them and nothing will be digested, the tank will then sludge up rapidly and will need emptying and re-starting. The tanks that use an air pump to aid digestion contain different enzymes and are more effective BUT without oxygen or anything to digest the enzymes will die, so leaving the property empty for extended periods or switching the pump off must be avoided. Mains drainage would be nice to have, but it does mean the cost of water doubles and the amount therefore saved pays for emptying every 10 years (I hope).