Iron filter

[Bill Sinclair]

1. Hi,
   I just installed an Iron filter that backwashes every 2 weeks. ( up to 100 gallons ea )
   My well tank and filter are in the basement.
   I'm also on a brand new septic system.
   I do not believe I should flush all the backwash through the septic system.
   I will be installing a French drain and if needed a drywell at the end of it. ( I don't really believe I'll need the drywell but will reconsider if a pro on here believes it's needed )
   I'm coming off the filter head with 1/2" tube and will be increasing that to 3/4" where it will go up to the joists with a 3/4" check valve on the rise. Then across the joists ( about 8 feet, then down to the spot where I'll go through the wall below the frostline. Then increase to 1" just before it punches through the basement wall and will continue ( graded down ) for 25-30 feet before it will change to the french drain. The french drain will be socked and perforated 4" PVC. for another 25 feet.
   
   Now..... the BIG question. I understand the "air-gap" requirement if tying into a septic line.
   However since this is feeding into a dedicated French drain and I have a check valve, how necessary is the air gap?
   And if totally un avoidable how and where would I do this? Especially considering it will be "jetting" out of the tube at 40PSI, not just gravity fed.
   
   Thank you

 

[Bannerman]

What does your county require for how water treatment equipment is to be discharged?

An air gap is utilized to prevent the potential for cross contamination in the unlikely event of a drain backup. Your filter will be utilized for conditioning potable water for your famiyly's consumption, so prevention of contamination is essential.

You could incorporate an air gap to feed into a larger diameter drain pipe which will drop vertically to where you plan to exit through the basement wall to the exterior. The smaller diameter line from the filter will remain pressurized, but the pressure will be dissipated in the air gap so all further flow will occur by gravity.

Since the air gap location will likely be 6' or 7' above the exit point and likely 1' or more above ground level, it is unlikely water will ever backup to the air gap, so the air gap will mostly serve to decouple the pressure line from the gravity drain, allowing air to enter to allow gravity flow to drain without restriction while also reducing the potential for a vacuum being placed on the drain line from the filter.

When the drain line from a filter or softener is very long and causes the water to be discharged lower than the unit, it is advisable to install a vacuum breaker at the drain line's highest elevation.

Whenever pressurized flow ceases, the water remaining within the drain line will be forced to drain by gravity. This can cause a vacuum situation within the drain line. If electrical power had stopped or the well pump was shut down during the filter's Backwash cycle, the media tank would be subjected to vacuum from the drain line which could cause the media tank to become crushed. Media tanks are designed for positive pressure so even a moderate vacuum condition can damage the tank.

A vaccum breaker at the drain line high spot will remain closed while under pressure, but when subjected to vacuum, will allow air to enter which will allow the downstream drain line to rapidly drain while eliminating vacuum on the media tank.

How was the backwash frequency determined? 2-weeks seems unusually infrequent for iron removal media.

 

[Sponsor]

 

[Bill Sinclair]

What does your county require for how water treatment equipment is to be discharged?

An air gap is utilized to prevent the potential for cross contamination in the unlikely event of a drain backup. Your filter will be utilized for conditioning potable water for your famiyly's consumption, so prevention of contamination is essential.

You could incorporate an air gap to feed into a larger diameter drain pipe which will drop vertically to where you plan to exit through the basement wall to the exterior. The smaller diameter line from the filter will remain pressurized, but the pressure will be dissipated in the air gap so all further flow will occur by gravity.

Since the air gap location will likely be 6' or 7' above the exit point and likely 1' or more above ground level, it is unlikely water will ever backup to the air gap, so the air gap will mostly serve to decouple the pressure line from the gravity drain, allowing air to enter to allow gravity flow to drain without restriction while also reducing the potential for a vacuum being placed on the drain line from the filter.

When the drain line from a filter or softener is very long and causes the water to be discharged lower than the unit, it is advisable to install a vacuum breaker at the drain line's highest elevation.

Whenever pressurized flow ceases, the water remaining within the drain line will be forced to drain by gravity. This can cause a vacuum situation within the drain line. If electrical power had stopped or the well pump was shut down during the filter's Backwash cycle, the media tank would be subjected to vacuum from the drain line which could cause the media tank to become crushed. Media tanks are designed for positive pressure so even a moderate vacuum condition can damage the tank.

A vaccum breaker at the drain line high spot will remain closed while under pressure, but when subjected to vacuum, will allow air to enter which will allow the downstream drain line to rapidly drain while eliminating vacuum on the media tank.

How was the backwash frequency determined? 2-weeks seems unusually infrequent for iron removal media.

 

[Bill Sinclair]

The discharge from the filter is appx. 4 feet from the floor.
The bottom of the joists above is only just over 6 feet.
The exit in the basement wall will be roughly 40" from the floor.
This is roughly 8" below the discharge fitting.
Can you recommend a practical way to insert some manner of basin with a trap that will catch water at 40 psi from a 1/2" tube and not splatter all over the place within the less than 3 feet left to work with and that also will not expose the joists and floor above to moisture and potential for mold.
I don't know of anything on the market but I am very crafty if you have any suggestions.
Also, if I have to go up to a basin to allow for the air break, it seems a vac break will be unnecessary, right?

The backwash frequency was the pre-set default from the factory.
It is adjustable via the control unit.
Once I move in and can monitor the filter I can fine tune it.
I actually just set it up to either 6 or 8 weeks since we're not living there we have very little water usage.

Any suggestions welcome. See photo attached to see set up before discharge is piped in.

 

[Reach4]

How many GPM?

https://airgap.com/product/ag100-001/ is rated for 12.5. You would use a 2-inch pipe below.

https://terrylove.com/forums/index....-for-softeners-and-backwashing-filters.64755/ discusses making an air gap from PVC fittings.

 

[Bill Sinclair]

How many GPM?

https://airgap.com/product/ag100-001/ is rated for 12.5. You would use a 2-inch pipe below.

https://terrylove.com/forums/index....-for-softeners-and-backwashing-filters.64755/ discusses making an air gap from PVC fittings.

I'm not sure of the GPM.
Where can I find that? I've looked in the manual and do not see it. Is there somewhere I can look or will I need to run the discharge into a bucket with a stopwatch?
I'm still a little hazy on how to run this line into an air gap and into a 2-in pipe with a trap and out the wall in such a short distance without the potential for it backing up at the trap since so much water is flowing so fast. Or am I over-analyzing this?
Is there a diagram for photo available to show me how this will work?
Thank you
Bill

 

[Bannerman]

Here is an example of one type of commercially available air gap fittings. The additional photos ehows how the fitting would be placed into a 2" standpipe.
https://www.homedepot.com/p/KEENEY-2-in-Plastic-Water-Softener-Air-Gap-PP855-69/204374532

The standpipe could then drop into a P trap before exiting through the basement wall to flow to your French drain/drywell. While the P trap may not be required as it will not be preventing sewer gas from entering the home, it may provide a barrier against insects from entering in consideration of the low backwash frequency.

As the long drain line is not vented, it may create suction to draw water out from the P trap, but I anticipate water flow may not be sufficient to completely fill a 2" diameter horizontal drain pipe to cause all of the water to be drawn from the P trap.

As a precaution, the long drain line flowing to the drywell maybe easily vented by utilizing a Tee and a riser pipe outside of the foundation wall, rising to just above grade level. The riser pipe maybe left open, or an air admittance valve utilized to cap the riser and prevent animal entry. The exterior riser maybe 1.5" as it will be only utilized to allow air to enter which will break any suction caused by the long horizontal run to the drywell.
https://www.homedepot.com/p/Oatey-S...20-DFU-Branch-and-8-DFU-Stack-39230/205395535

The photo you included, seems to show what I anticipate is a 9" X 48" or possibly a 10" X 54" media tank equipped with what appears maybe a Fleck 5600 control valve.

What media does the tank contain? What amount of iron is within your well water?

 

[Reach4]

Where can I find that? I've looked in the manual and do not see it. Is there somewhere I can look or will I need to run the discharge into a bucket with a stopwatch?

If the literature available for your iron filter does not say, ask your dealer what it should be. But yes, if you can play the drain into a 5 gallon bucket during backwash, and if S is the number of second to fill, the flow is is (3oo/S) gpm.

Fleck 5600 is only good for about 7 gpm. That is lower than what many iron media need for a 10 inch diameter tank.

I also agree that backwash every 2 weeks is an unusually long period.

 

[Skyjumper]

youre making this way too complicated.

if you have a basement, you almost certainly have a sump pump. direct the filter discharge into the sump. done.

if you don't have a sump then you must have huge slope outside to run the foundation drain to daylight. in this case run the filter discharge into a 1.5" sch40 pipe up in the floor joists above, and slope it slightly down and run it out of the house above grade and then 90 it down into a 4" PVC pipe that goes down 3ft or so and then runs out to daylight. keep it sloped, make sure it doesn't pool at the end. that will never freeze. no french drain or drywell needed. the gap between the 1.5" pipe and the 4" pipe is your air gap.

2 week backwashes is way too long for an iron filter.

here's how I did mine. I also tied in the downspout. this pipe goes 250ft and exits to daylight at the back end of my property where the grade drops off. has never frozen. and this is obviously not 3ft deep (had to keep it shallow to maintain slope the entire 250ft)

 

[Bill Sinclair]

Bannerman, I'm not sure what the media is. It is a Pro+Aqua Pro-well-1E whole house well water filter. SEE IT HERE
https://proaquawater.com/products/pro-well-1e-whole-house-well-water-filtration-system.
I don't have the health dept report with me so I can't say what the true percentage of iron is but the water was very noticeably brown and quickly left rust stains in the toilet, tub and sink . This is a brand new 160 ft. deep well
I believe I've grasped what you are suggesting and made a drawing . I did draw it with the AAV on the inside of the basement wall rather than outside the wall. Will my layout as drawn be a viable and code worth solution?

 

[Bill Sinclair]

youre making this way too complicated.

if you have a basement, you almost certainly have a sump pump. direct the filter discharge into the sump. done.

if you don't have a sump then you must have huge slope outside to run the foundation drain to daylight. in this case run the filter discharge into a 1.5" sch40 pipe up in the floor joists above, and slope it slightly down and run it out of the house above grade and then 90 it down into a 4" PVC pipe that goes down 3ft or so and then runs out to daylight. keep it sloped, make sure it doesn't pool at the end. that will never freeze. no french drain or drywell needed. the gap between the 1.5" pipe and the 4" pipe is your air gap.

2 week backwashes is way too long for an iron filter.

here's how I did mine. I also tied in the downspout. this pipe goes 250ft and exits to daylight at the back end of my property where the grade drops off. has never frozen. and this is obviously not 3ft deep (had to keep it shallow to maintain slope the entire 250ft)
View attachment 75861

Thanks for your feed back.
I do not have an installed sum pump. I understand there was an outside perimeter French drain installed when the house was built 60 years ago but I'm pretty certain this is long ago collapsed ( and also not in my current budget to dig up and replace )

Given a choice to dig a 250 ft trench to the rear of my property and digging 40 or 50 ft trench and dropping in perforated pipe, for me the 250 feet is not even a consideration. ( I'm old and digging gets tiring )

I also do not want any part of this above the frost line and the above the surface air gap will not meet this requirement.
SO the air gap must be inside and the pipe must exit the basement below the frost line.

In my area I've actually had 4" sch 40 PVC waste pipe, vertical for 20 ft. but on the outside of the building, freeze solid and bust, so I'm taking no chances.

Thanks again for your suggestions.

Take a look at my drawing in the previous post. this looks pretty simple.

Bill

 

[Skyjumper]

Thanks for your feed back.
I do not have an installed sum pump. I understand there was an outside perimeter French drain installed when the house was built 60 years ago but I'm pretty certain this is long ago collapsed ( and also not in my current budget to dig up and replace )

Given a choice to dig a 250 ft trench to the rear of my property and digging 40 or 50 ft trench and dropping in perforated pipe, for me the 250 feet is not even a consideration. ( I'm old and digging gets tiring )

I also do not want any part of this above the frost line and the above the surface air gap will not meet this requirement.
SO the air gap must be inside and the pipe must exit the basement below the frost line.

In my area I've actually had 4" sch 40 PVC waste pipe, vertical for 20 ft. but on the outside of the building, freeze solid and bust, so I'm taking no chances.

Thanks again for your suggestions.

Take a look at my drawing in the previous post. this looks pretty simple.

Bill

okay, but the problem with your plan is that you assume an underground french drain with no exit to the surface **below the exit from the iron filter** will have the capacity to absorb all the water. I have my doubts. after a few cycles it will probably saturate and then water will back up into the house. and completely saturate the earth around your foundation. then you'll have a big problem to solve.

not sure what you mean by 20ft vertical pipe froze solid... not 20ft below grade it didn't, even at the surface unless it was plugged and full of water...

btw I live in Chicago we get -20F almost every winter... my drain has been in 7 years never froze. keep the water moving it will not freeze.

you are going to spend a small fortune excavating down to install your deep french drain, and bore a hole through your foundation that will invite future water leaks... too many risks, too much money, when there are better options. if you are going to dig this yourself by hand I'd suggest going out there and trying a few feet first.. you will quick see how difficult it is to dig a 4ft deep, 40ft trench without a backhoe... much easier to dig a shallow 250ft sloped trench.

 

[Reach4]

I also do not want any part of this above the frost line and the above the surface air gap will not meet this requirement.
SO the air gap must be inside and the pipe must exit the basement below the frost line.

What Skyjumper suggests will work. What could happen in very cold weather is that you would get a layer of ice. To help clear the pipe, you would want to have good slope and a vacuum breaker at the highest point to let the water out quickly.

We are skeptical that your iron filter is going to work as you hope.

 

[Bill Sinclair]

What Skyjumper suggests will work. What could happen in very cold weather is that you would get a layer of ice. To help clear the pipe, you would want to have good slope and a vacuum breaker at the highest point to let the water out quickly.

We are skeptical that your iron filter is going to work as you hope.

Not sure what is meant by the iron filter is not going to work as hoped.
Please explain.
As far it's filtering, it is working splendidly. The water is clear and odor free and tastes good.

As for the drain, my original plan was to place it only below the frost line. and if a drywell was needed to handle the flow then add that to the end.
I guess I could bring it to the surface as long as I'm careful where I end it. Would the drywell or daylight options resolve the concerns of over saturation?

Note to Skyjumper, the 4" vertical drain was on the 'outside' of the bldg. it carried the waste from second floor bathroom.

Oh, what should be an average backwash frequency in a home with two adult occupants?

 

[Reach4]

Not sure what is meant by the iron filter is not going to work as hoped.
Please explain.
As far it's filtering, it is working splendidly. The water is clear and odor free and tastes good.

That is great. I hope that continues. If it does, that will be informative as well as good for you. If it does not continue, contact your seller. The advice is likely to be some cleaning or treatment on a regular basis.

What I was saying that often iron filters don't always work for many months, and those that do usually get backwashed more frequently. Backwashing should expand the media. Because your tank is painted, you cannot see the expansion by shining a light.

My backwashing iron+H2S filter works for me, but my iron is only about 0.4 ppm (mg/l). Mine regens with backwash every 3 days, and it gets treated by a bleach solution during each regen. It needs less gpm than most.

 

[Bannerman]

Yes, your drawing is as I described. I envisioned the P trap closer to the wall so there would be no room remaining to install a Tee and riser before penetrating the wall. The check valve is not required. One suggestion is to extend the vent riser further above the pipe to reduce the potential for water to rise in the vent riser as unlikely as that may be.

With regard to code compliance, the piping part is not connected to your septic system and so does not fall under usual plumbing code. I had asked about your county requirements for discharging directly to the environment as that is a seperate matter from plumbing.

Since the discharge is plain water that will contain oxidized iron that was originally dissolved in the well water in a ferrous form that would oxidize when exposed to air anyway, I anticipate there should be no issue with that discharge, but if the unit was a softener, there could be an issue due to higher levels of sodium and chloride.

The filter sales literature does show a Fleck 5600SXT mounted on a 9" X 48" media tank. That tank dimension is appropriate for 1 cubic foot of media. Unfortunately, the media is not specified but as it states it will provide 3 micron filtration, I suspect the media may be Katalox Light.

The recommended backwash rate for KL in a 9"diameter tank is from 4.4 to 6.6 GPM with 60°F water temperature, but often, a slightly higher flow rate will be beneficial. If your water temperature is cooler than 60°F, then that will provide additional media lift and reclassification. The maximum rated backwash rate for a Fleck 5600 is 7GPM so that will likely be the max even if the drain flow restrictor were to be removed.

KL will be typically backwashed every 3-days, but that may vary depending on the iron level in your water. As the thread below includes an Arsenic issue, Ditttohead recommended to extend the KL backwash frequency to 4-7 days.
https://terrylove.com/forums/index.php?threads/arsenic-removal-water-questions.89413/#post-641786

This is what can happen to Iron reduction media with insufficient backwash frequency.

https://terrylove.com/forums/index.php?threads/iron-filter-noise.90488/#post-650780

 

[Bill Sinclair]

Bannerman,
Thank you for all of your advise and especially this last in depth answer.
Just for the record I intend to have the filter backwash as often as is needed/recommended. It is just that the house is vacant and the only water use is occasionally when I'm there working.
Also, while it may not be evident in my drawing, the "P" trap is flat against the wall and the end where it goes thru the wall is a 90 degree turn into the wall.
I am still curious about your view on the 18" to 24" inch deep perf pipe. What I have is sleeved and I will also be laying a bed of stones and sheet filter cloth and covered with stone, filter cloth, and soil.
I can run it back out of the ground but the yard is really flat and this would require going back up hill to exit the ground.
This is why I thought a drywell would help.
For the record, this place had a drywell for all sewage and waste water ( in spite of not being legal for decades ) before I bought it. ( elsewhere in the yard )
I insisted that if they wanted to sell the place that had to be put out of service and a new, proper septic tank and drain field put in.
this dry well functioned for 60 years so I figured the soil should handle the backwash. Am I wrong for that presumption?

PS: I'm not trying to challenge anyone here, I am trying to learn.

 

[Bill Sinclair]

Yes, your drawing is as I described. I envisioned the P trap closer to the wall so there would be no room remaining to install a Tee and riser before penetrating the wall. The check valve is not required. One suggestion is to extend the vent riser further above the pipe to reduce the potential for water to rise in the vent riser as unlikely as that may be.

With regard to code compliance, the piping part is not connected to your septic system and so does not fall under usual plumbing code. I had asked about your county requirements for discharging directly to the environment as that is a seperate matter from plumbing.

Since the discharge is plain water that will contain oxidized iron that was originally dissolved in the well water in a ferrous form that would oxidize when exposed to air anyway, I anticipate there should be no issue with that discharge, but if the unit was a softener, there could be an issue due to higher levels of sodium and chloride.

The filter sales literature does show a Fleck 5600SXT mounted on a 9" X 48" media tank. That tank dimension is appropriate for 1 cubic foot of media. Unfortunately, the media is not specified but as it states it will provide 3 micron filtration, I suspect the media may be Katalox Light.

The recommended backwash rate for KL in a 9"diameter tank is from 4.4 to 6.6 GPM with 60°F water temperature, but often, a slightly higher flow rate will be beneficial. If your water temperature is cooler than 60°F, then that will provide additional media lift and reclassification. The maximum rated backwash rate for a Fleck 5600 is 7GPM so that will likely be the max even if the drain flow restrictor were to be removed.

KL will be typically backwashed every 3-days, but that may vary depending on the iron level in your water. As the thread below includes an Arsenic issue, Ditttohead recommended to extend the KL backwash frequency to 4-7 days.
https://terrylove.com/forums/index.php?threads/arsenic-removal-water-questions.89413/#post-641786

This is what can happen to Iron reduction media with insufficient backwash frequency.

https://terrylove.com/forums/index.php?threads/iron-filter-noise.90488/#post-650780

Bannerman, did I lose you?

 

[Bannerman]

The French drain is basically equal to a single length of septic drain field run which because the discharge is limited and only periodic, I expect it should work just fine.

The depth maybe an issue during winter since the French drain is not below frost line. Unlike Skyjumper's shallow example, your installation will not discharge to open air. While your 30' length of supply pipe will drain rapidly when water is quickly absorbed into the ground, I don't know if there will be any possibility of slowdown to cause water to freeze in the supply pipe when ground absorption is slowed while the ground is frozen within the French drain. A Tee'd off section of perf pipe that rises slightly before dropping down into a deeper drywell just prior to the perforated section, could provide a secondary drain to ensure water will drain even if the main absorption bed becomes frozen.

The question is, if a drywell is needed regardless, is there any point to the 25' length of French drain?

 

[Bill Sinclair]

5

The French drain is basically equal to a single length of septic drain field run which because the discharge is limited and only periodic, I expect it should work just fine.

The depth maybe an issue during winter since the French drain is not below frost line. Unlike Skyjumper's shallow example, your installation will not discharge to open air. While your 30' length of supply pipe will drain rapidly when water is quickly absorbed into the ground, I don't know if there will be any possibility of slowdown to cause water to freeze in the supply pipe when ground absorption is slowed while the ground is frozen within the French drain. A Tee'd off section of perf pipe that rises slightly before dropping down into a deeper drywell just prior to the perforated section, could provide a secondary drain to ensure water will drain even if the main absorption bed becomes frozen.

The question is, if a drywell is needed regardless, is there any point to the 25' length of French drain?

Now I'm concerned, but not about the backwash drain.
The fellow who put my well in told me the well pipe From the well to the house was 18" to 20" deep and based on where it penetrates the basement wall I'm inclined to believe it. He said that's the average depth he buries the well pipes in this area. He said he's never had a call back for one that froze. So I presumed that was a safe distance for the drain line. I was figuring that if I dug a 24 to 30 deep trench that got deeper as it continued, to allow adequate slope would be good on the drain since the well pipe was only 18 in deep.
Thinking that even with a few inches of gravel under the perf pipe it should be safe, but now I'm thinking, maybe not.

Seems like the more questions I ask the more questions pop up.