Septic tank and chemicals

Call me Al

We have had an incident where we've had to drain all the water out of our house water tanks into the septic tank due to toxic levels of chlorine.
I'm unsure now how our system will handle all the chlorine.
How will we know if the microbe system has been killed off? And how do we get it back up and running again if it has been killed off? Fwiw it's a bord na Mona system installed about 12 years ago and working fine for the most part although we do probably need to change/replenish the moss peat at some stage this year.
Thanks

my3cents

I wouldn't worry too much, the amount of organic matter in a septic tank will make short work of the small amount of chlorine in ordinary tap water and thats the end of it. Chlorine is just an oxidizing agent and once the reaction has taken place there is nothing left that will upset the septic tank.

eoinfitzokk

Any idea on volumes to drain or concentration of the bleach (likely sodium hypochlorite)? Chrlorination of pipes requires 5ppm from memory.

If it wanted to try avoid the discharge, you could block the pipe at the closest manhole to the septic tank and ask a local farmer to suck out the water using a hose. If the farmer can dispose of the water for you, then well and good, if not you could try drip feeding the water back into the tank slowly whilst running the water from your house to provide decent dilution. This way you preventing the a possible shock discharge.

Your second option is to neutralize the bleach with ascorbic acid.

Third option is lots and lots of dilution of water down the foul sewer when flushing out the bleach.

Call me Al

eoinfitzokk wrote: »

Any idea on volumes to drain or concentration of the bleach (likely sodium hypochlorite)? Chrlorination of pipes requires 5ppm from memory.

If it wanted to try avoid the discharge, you could block the pipe at the closest manhole to the septic tank and ask a local farmer to suck out the water using a hose. If the farmer can dispose of the water for you, then well and good, if not you could try drip feeding the water back into the tank slowly whilst running the water from your house to provide decent dilution. This way you preventing the a possible shock discharge.

Your second option is to neutralize the bleach with ascorbic acid.

Third option is lots and lots of dilution of water down the foul sewer when flushing out the bleach.

Thanks; it was higher than 5ppm.

6.9 at one point further down the line from me.
Unfortunately we have no idea how long the levels were excessive. although there is quite strong evidence that it was very high last week too, so it has been pumping through our system with at least a week so I'd imagine damage has been done already. Yesterday we were told to flush the tanks completely which we just had to do at the time.
I've been trying to keep a rap running 8n the hope it'd dilute the chemical.
Unfortunately we have also not been told the type of chlorine involved or the actual quantities.