kd Posted May 3, 2006 Share Posted May 3, 2006 The inspection pipe, which is situated 10 metres from my 3000 litre fosse tank, is full of water. Because of this my fosse is not working properly as water cannot exit the tank.I cannot understand how water can remain in this 10 m stretch, which I believe is called the filter bed, as I assume it consists of 100mm pipe(s) which are holed/slotted to allow water to soak into the ground below. As the weather has been quite dry recently I do not believe the ground is full of rainwater so why does the water not escape into the ground. 15 metres further is another up-pipe/inspection pipe into which I poked a stick and realised that there was soil in it. Surely this cannot be the problem as it is 25 metres from the fosse tank.I am reluctant to dig up the ground as the gite letting season commences soon, so how can I discover the problem without digging.All responses appreciated - thanks. Link to comment Share on other sites More sharing options...
Payrac-man Posted May 3, 2006 Share Posted May 3, 2006 Hi,It sounds like the filter bed is clogged. When was the fosse last pumped out? If solids have exited the fosse into the filter bed it will need to be re-dug. also check the groundwater level and compare it to the exit pipe level, if the water level is too high this causes back filling. How old is the system? Link to comment Share on other sites More sharing options...
Jhc Posted May 3, 2006 Share Posted May 3, 2006 Hi - we had a problem with ours v recently and I posted some questions about it on the house renovation thread. We eventually found out that our filter pipes were partially blocked because the fosse septique was not working properly (YUK!). We have no idea why not, but the organisms in it seemed to have entirely died as they were not working and raw'ish sewage was exiting into the filter bed pipes and blocking them. We had definitely not used any bleach etc so cannot understand it, plus we had the fosse emptied about 1 year ago. Take the lid off your fosse septique if you can, and if there is a mass of material floating at the top of the chamber nearest the exit pipe, then its not working and the material will be exiting into your filter bed and blocking it. We managed to buy 2 pots of 'fosse recharge' from the hardware store which promised to 'shock' it into life and appears to have worked. The next time I took the lid off the fosse there was no real mass of sewage and toilet paper (as earlier) and it appeared to be 'fizzing' which I took to be the organisms letting off gas and a good sign. We then flushed out our filter bed pipes with lots of water and we appear to have cleared them. I would be interested to hear how you resolve your difficulties as we are now nervous about the fosse - like you we have gite guests arriving and using that fosse from Saturday. Good luck. Link to comment Share on other sites More sharing options...
Monika Posted May 4, 2006 Share Posted May 4, 2006 The answers were of great interest to me as we have just had a fosse installed. In our case, a pump pumps the water up quite a steep slope to the filter bed. What if this pump fails? Does the pump need to be on all the time, even if we are away.How do we know the pump is working? The fosse has not been used yet but there is already water in the chambers at the filter bed? Link to comment Share on other sites More sharing options...
cheminot Posted May 4, 2006 Share Posted May 4, 2006 [quote user="Monika"]The answers were of great interest to me as we have just had a fosse installed. In our case, a pump pumps the water up quite a steep slope to the filter bed. What if this pump fails? Does the pump need to be on all the time, even if we are away.How do we know the pump is working? The fosse has not been used yet but there is already water in the chambers at the filter bed? [/quote]Your pump should be operated by a float switch which switches the pump on when the water reaches a certain level and cuts out again when the level drops. It will probably be located somewhere on the top of the fosse and resembles a toilet cistern ball fixed to a rod with the actual switch on the top end. When the water level reaches the ball it floats up and operates the switch which starts the pump.If you are worried about pump failure you can install a second pump in parallel with the first with its own switch set slightly higher in the fosse. Thus, if the first pump fails the second will cut in shortly afterwards and if an alarm is also fitted it will automatically warn you that there is a problem. Of course this additional equipment comes at a price!If you havent got anything like this then it sounds as if you have to operate it manually and will have to keep a close eye on the fosse level, but provided it is only grey water from the house goes in it then it should not keep filling while you are away.cheminot Link to comment Share on other sites More sharing options...
Monika Posted May 5, 2006 Share Posted May 5, 2006 Hi Cheminot, thanks very much for your explanation. I think it is the float type pump and good to know we don't have to do it manually! Is your Avatar Swanage Railway? Link to comment Share on other sites More sharing options...
cheminot Posted May 5, 2006 Share Posted May 5, 2006 [quote user="Monika"] Is your Avatar Swanage Railway? [/quote]No, its the 'City of Truro' in Laira Depot at Plymouth, which is where I 'travaille'. Link to comment Share on other sites More sharing options...
kd Posted May 9, 2006 Author Share Posted May 9, 2006 I have discovered that my fosse is probably about 20 yrs old. I have spoken with various people regarding my fosse and have concluded that the problem is one of the following:-1. over the last 20 years the slotted filter pipes have become clogged with grease etc thus not allowing the water to exit2. the slotted filter pipes are surrounded by soil instead of gravel3. the ground water levels are high and the pipes will empty during the dry spell (unlikely wishful thinking)I poured hydrochloric acid into the inspection pipe and also at the exit (towards the filter bed) of the fosse tank however, I have been informed (by a man who empties fosses) that this is unlikely to work. It seems the best solution is to wait for the dry period (just in case that resolves the problem) and if the problem persists then dig a 40cm hole at the inspection pipe to investigate and then maybe call out the fosse man who would now have good access to the pipes to use his equipment to flush through the pipes in both directions and hopefully clear any problems. If this doesn't work it means digging and relaying filter bed.KD Link to comment Share on other sites More sharing options...
Tony the Turner Posted May 10, 2006 Share Posted May 10, 2006 If your little microbes have "died", a good dosing with Septifos or similar will revive them. We have had a fosse at our residence secondaire for 13 years and I suspect that it was at least 10 years old when we bought. We always add two doses of Septifos when we arrive for a stay and then a dose weekly. Our microbes seem very happy and chomp away at the gunge to the extent that when we have our 4 /5 yearly empty what comes out is virtually all liquid. Obviously that won't help with your bunged-up pipes but would be good preventative maintenance for the future. Link to comment Share on other sites More sharing options...
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