emergency overflow drain

[captstinky]

I posted on another forum and got a super fast response- this site has been a great resource!!

Heres my deal: I am putting a tank in wall between our kitchen/den. The tank is close to the sewage drain in the kitchen. I would like to plumb an emergency overflow from the sump to the sewage line, so if power goes out and the sump fills- water overflows into the sewage line and not between the walls. The sump is a bit on the small side, but its what we have, and what space currently allows.

I am concerned about bacteria from the sewage line entering my tank system. I thought about a p-trap, but that would dry up without periodic overflowing.

I am considering hanging an old prefilter on the side, which would allow visual monitoring of the water level, keeping the prefilter 'primed' but think the water will eventually sour and cause bacterial issues. The prefilter doesn't really solve the bacteria issue, but keeps the drain 'ready'

I thought about some kind of float switch, but that may get a bit complicated. My vision is some kind of reverse guillatine or cigar end cutter, that would use styrofoam to open a gate as water rose.

What about a bulkhead in the side of the sump, 90 degree elbow facing up, with a toilet flange on top, hooked up to a large foam float. Won't open until water rises above it...

I am curious to hear how others have approached this situation

 

[DonW]

Here is what I see happening with a system like that. Power goes out for 5 minutes while your at work. The overflow water goes to the sewer. Then the power comes back on. Now your left with a return pump sucking air and a big problem if your using an ato with kalk.
I think it would be wise to work on preventing the back siphon. Should be hard. Why dont you tell us about your sump and tank?

Don

 

[captstinky]

I'll try to take a pic and measure the sump capacity- I think sump is 5-7g, with a 40g tank. Plan to put a 30g refugium inline. All the tanks are pretty close together, so not too much in linear feet of plumbing.

Very good point on short power outage. I do not have any auto dosers at this point, and may not in the near future. But I like to plan for expansion rather than pain myself into a corner-which I may have done with such a small sump.

 

[LakeEd]

I agree... many power outages happen while we aren't home to monitor them, and are relitivly short lived.

Do you have a good siphon break on your return lines up to your tank from your sump? Is there enough room in your sump for the small amonut of liquid that is in your return lines? If not, is it possible to run your sump at a slightly lower level, that would allow the expansion space???

 

[mmkeeper]

If you are going to be going directly into a sewer waste line I would more concerned with venting sewer gas into the sump area then the house. The p trap would stop that. Is the sewer line closes to a sink or bathroom?

 

[captstinky]

No system photos yet, my other half had me installing lighting thisweekend. Sewage line is closest to a sink, in the kitchen. No good siphon break the way the system is set up, but I have a back flow prevention valve on the pump, though. The tank is not set up yet, so still a little bit of room for modification.