Indirect piping softener drain to standpipe

[Gsmith22]

Posting this here rather than the softener forum because I think I will get better "plumbing" responses as that is what this question(s) is really about.

Have a water softener (cation exchange) tank, anion exchange tank, and carbon tank as part of my well water treatment that all have drain lines for backwashing/regeneration. The tanks are all located in my basement but all plumbing drainage pipes are overhead (basement is unfinished, no floor drains, sinks, showers, etc. in basement). I had been making due with a makeshift drain system from a prior owner softener rig job (hose routed through floor to laundry tub/dont' get me started on this guy's various rigged systems) that I want to correct and be properly done per code (which is 2018 NSPC in NJ). I intend to install a 2" standpipe with trap and AAV to vent the trap attached to one of the overhead drain lines in the basement. This new standpipe will be positioned so that the standpipe opening is up near the underside of the first floor - see last post #14 in this thread for exactly what I intend to do: https://terrylove.com/forums/index....ner-to-overhead-sewer-line.80481/#post-582297

The issue that I am trying to figure out is that my water line comes into the house at the opposite end of my basement than the main drain line exiting to the septic system. So where the tanks are all located, the overhead drains are all up too high to incorporate the standpipe. The standpipe can't be installed closer than ~60ft from the tanks. This means that the indirect piping from the water treatment tanks is going to be ~60ft as well.

1. I keep reading that indirect piping can't be over 15ft long (although I can't find that direct restriction in the NSPC Chapter 9 http://epubs.iapmo.org/NSPC/NJ2018/mobile/index.html#p=130). Can anyone point to this being the case? My HVAC condensate lines are definitely more than 15ft and that was approved by plumbing inspections.

2. I have also read that the indirect piping has to have a trap when 10 or longer but for the life of me I can't see what that does since this pipe would not connect to the drainage system (it will have an air gap at standpipe). There is an exception to clear water wastes (which I think is what comes out of these water tanks).

3. Finally, do you think I need to run three separate drain lines from the tanks to the standpipe or could I combine the lines into a single drainage pipe and run one line from the tanks over to the standpipe? The tanks don't backwash at the same time so the indirect line could be sized for one tank backwashing but I wasn't sure about some issue with the drainage from one tank commingling with the drainage from another. When one tank runs, it pressurizes the line (via the house water pressure) and essentially would pressurize the drain line of non back washing tanks when one of them is back washing (since they would be connected into a common manifold)

Hoping someone has done this and I am not reinventing the wheel

 

[Reach4]

I had been making due with a makeshift drain system from a prior owner softener rig job (hose routed through floor to laundry tub/dont' get me started on this guy's various rigged systems)

Running a pipe to the laundry tub on the floor above is not a problem in itself, but you probably had something that made it hokey.

I keep reading that indirect piping can't be over 15ft long

That might be for restaurant sinks or some such. I don't think a softener or backwashing filter would be considered indirect piping until the air gap.

3. Finally, do you think I need to run three separate drain lines from the tanks to the standpipe or could I combine the lines into a single drainage pipe and run one line from the tanks over to the standpipe?

Yes. Run at least 3/4 inch pipe. PVC would be good, as would be PEX. PVC would be better in that 3/4 pvc is bigger ID than 3/4 pex.

You could also consider putting in a dry well. That would involve some digging. You may find somebody who does digging for a reasonable price.

 

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[Gsmith22]

Laundry tub - the routing to the laundry tub looks like crap (that is being kind) - multiple pipes coming out of the floor held down to top of tub, its loud when running/splashing into tub base, and generally exudes a complete lack of professionalism. It may be "okay" from a functional state but I hate it. Plus, we have a laundry room reconfiguration/renovation coming up so sink/tub isn't staying where it currently is; I need a solution that I don' t have to resolve again in a couple of months. Which led me to the standpipe in the basement on the overhead lines.

Indirect piping - Based on how an "indirect waste pipe" is defined http://epubs.iapmo.org/NSPC/NJ2018/mobile/index.html#p=28 I don't think your interpretation is correct. Basically an indirect waste pipe is all of the piping that isn't directly connected to the drainage system - ie its all the piping that occurs prior to an air break/air gap where conveyance to the plumbing system is made. So that would make all of the piping from the softener to the air gap indirect piping - the diagram they have for this too seems to confirm that interpretation. I don't see a length limitation in the NSPC (there is apparently a 15' limitation in UPC). I just wanted to make sure my 60' long pipe isn't crazy for some reason not clear to me. Why would a trap be necessary on this indirect piping once it goes over 10ft (NSPC requirement)? There is a clear water waste exception to the trap so I think I can do without but more curious from a practical standpoint since the indirect pipe isn't connected to a source of sewer gas.

Confirming what I thought about the piping, each tank needs its own drainage line to the air gap above the standpipe and can't combine them into one drainage pipe. I figured as much but wanted to see if my interpretation was correct. I wasn't real sure about providing back pressure on the drain lines of valves who were not also backwashing at the same time. Maybe could get away with check valves in the lines but that is just something else for the valve head to overcome when it is backwashing and I'm already a little leary of the distance (although it only goes up like 4' and horizontally 60')

 

[Reach4]

Indirect piping - Based on how an "indirect waste pipe" is defined http://epubs.iapmo.org/NSPC/NJ2018/mobile/index.html#p=28 I don't think your interpretation is correct. Basically an indirect waste pipe is all of the piping that isn't directly connected to the drainage system - ie its all the piping that occurs prior to an air break/air gap where conveyance to the plumbing system is made. So that would make all of the piping from the softener to the air gap indirect piping - the diagram they have for this too seems to confirm that interpretation. I don't see a length limitation in the NSPC (there is apparently a 15' limitation in UPC). I just wanted to make sure my 60' long pipe isn't crazy for some reason not clear to me.

Agree.

Confirming what I thought about the piping, each tank needs its own drainage line to the air gap above the standpipe and can't combine them into one drainage pipe.

Oops. You can combine. I am afraid I saw the second clause of your sentence " could I combine the lines into a single drainage pipe and run one line from the tanks over to the standpipe?" and said yes to that.

Is 3/4 PVC good for you?

 

[Gsmith22]

3/4 pvc is fine. i may still run seperate lines though. I'm not thrilled about putting backpressure on the drains/drain lines of the various tanks when one is in backwash/regeneration mode

 

[Reach4]

3/4 pvc is fine. i may still run seperate lines though. I'm not thrilled about putting backpressure on the drains/drain lines of the various tanks when one is in backwash/regeneration mode

OK. However think about what a seal on the non-backwashing device will feel: ~60 psi on the inside of the seal, and something less on the downstream side.