Backwash line

JayK

Well-known member
Feb 24, 2019
97
St. Louis
I have a 6" Schedule 40 pipe that serves to take the run off from my gutters to the street. I want to tie my 2" backwash line into that but the pool builder is telling me that it would backup due to too much friction and possibly come out my gutters on the roof! I'm having a hard time buying this, but I'm inclined to listen to him. Any thoughts?
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,459
Bedford, TX
Jay,

Total bull. Here in my area, it is a requirement to have all backwash lines connected to the house sewer line which is only 3 or 4".

I would be more worried about your city requirements.. Some have very strict rules about pool water going into the storm drains vs. the sewers...

Thanks.,

Jim R.
 

kevinp768

Active member
Sep 30, 2018
30
Wichita KS
I have my backwash line hooked to my underground drain for my gutters. its 4" schedule 40 pvc. Here in Wichita KS local code states we cant directly discharge pool filter backwash to either storm or sanitary sewer. Mine terminates to a pop up emitter in the yard about 3' away from a storm drain in my neighbors yard. Sometimes the extra pressure from backwash pops the emitter off the pipe but it takes me about a minute to put it right back on when im done.
 

cfherrman

TFP Guide
May 10, 2017
2,377
Hays, Kansas
If your backwash would fill up the 6" and then load it with enough pressure to start climbing the downspouts and then fill the gutters if your pump has enough head to get that high, it simply would drain back out when you shut the pump off.
 

JayK

Well-known member
Feb 24, 2019
97
St. Louis
So I did some research and came up with the following:
1: There's not enough water to really cause a "river" in people's yards. There's more than enough yard to soak it in.
2: You are correct in that you cannot drain to the street. (Which is what I was going to do)

Just gonna put a pop up in my yard and let the water soak in. I don't have access to a nearby sewer drain.
 

cfherrman

TFP Guide
May 10, 2017
2,377
Hays, Kansas
Currently my backwash line is 3' of 1 1/4 PVC, it just goes on the grass. I did that all last year and it gets gone soon enough. This year I'm gonna rig something up so it sprays the yard instead piles up.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,782
Pleasanton, CA
I would say it is going to depend on the setup.

If you hard plumb into the home's sewer line and the line is sealed and pressurized, it will offer back pressure to the pump to slow the flow rate and force water through the drain system at higher pressure at pretty much any flow rate. Although if the pressure is high enough it could force water out of the home's drains.

On the other hand, if there is a small section of hard plumbed pipe that empties into a non-sealed open pipe such as a french drain, this drain system will gravity drain and as such have a limited flow rate through the drain pipe depending on the elevation change so it could easily overflow.

If the backwash pipe empties into lawn or a catch basin and then is allowed to gravity drain from there at it's own rate, there is no issue.