We had our tank emptied when we moved in 10 months ago. It is now full to the top and needs emptied again. I hadn't expected to have to empty it every year - more like every 2-3 years and wondered whether the constant rain this year and saturated ground would affect its ability to drain?
You should only need to empty the tank of sludge.. The grey water, should drain away from an overflow pipe into a soakaway. If it is trying to drain into very sodden wet ground, it won't and eventually your toilet will start to back up and you'll have to be emptied again. We had this problem and had to dig a new soakaway pipe.
Wow, I can't believe that you could only empty it every 2 to 3 years. We have a septic tank system where the liquids, including all washing machine, rainwater, baths etc get pumped out to drain, but the solids etc stay in the tank and we empty it every 4 to 6 months.... We also get all the pipes water blasted at the time, so they keep working. It costs about £100 an empty, but that cost is pretty well off set by not paying for the water company drainage fee... I would just get it emptied or get your pump checked..
We had this problem too after a prolonged period of heavy rain. The ground was just too sodden for the soakaway to... soak away. Pain in the arse because by the time you realise there's a problem you end up needing to make an emergency call out for the poo wagon to come and empty it.
After a long rain here our water table is high, and we live up a hill, it'll take a few days and the level will drop again for us. But more rain due on Friday. We've pumped ours out three times in 19 years (just had it done in the summer) The pumper truck was at the neighbors the other day and told the owner not to pump it was rain water, it'll drain off no problem, they only want to pump the sludgy solids, water leaches off eventually.
Spoke to a nice lady at Scottish water who assured me it was normal for a septic tank to be full of water and it was when it filled with sediment that it needed emptied. Emergency empty was £350
Ingles where would the overflow pipe be. Should I be able to see it near the top somewhere? We think it may have come over the top of the tank at some point as there is a puddle of yucky water near the opening and I wonder if the overflow pipe may be blocked.