# Iron Filters - How to Manage Backflush



## Traderyoda (Aug 7, 2012)

This one's a little different challenge.....

A new waterfront house with a 4' crawlspace on a well with public sewer needs an iron filter installed. The house has good water, but with a fairly high iron level that causing other problems. The iron filter will be a Filox chemical free system that removes iron and other elements through a media bed. The system requires a significant amount of daily backflush (12-15 gpm for 15 minutes) to purge the iron from the bed. The question is what to do with the backflush water.

Because the house is on the water and flooding is something that has to be considered it's a bad idea to leave an open pipe that leads back to a potable water supply; code certainly doesn't allow it. The water can't get dumped outside because it will build up a stain, kill grass, etc.; and dumping it down the condensate line doesn't work because that line leads to a small french drain. So the solution provided by the manufacturer is to dump the backflush into the sewer line and use an air gap to prevent contamination. The problem with that idea is the local code doesn't allow ANY opening in the crawl space to or from a sewer; so air gaps won't work.

There's an added complication... the local county annually jets the sewer. They seem to be a little aggressive with the jetting because last time it actually pushed water and sewage out of a second floor toilet... much to the chagrin of the homeowners.

I haven't been able to find anyone who's tackled something like this before. My plan is go ahead and dump the backfliush into the sewer and isolate the iron filter using two devices. First, a backwater valve in the house's 4" PVC main drain to check any flow from the sewer into the house drain (the drain line runs through most of the crawlspace and is easy to get to). Then a 3/4" double checkvalve backflow preventer in the backflush line. I plan to "t" in the backflush line immediately upstream of the backwater valve since these devices have a weakness in that solids tend to build up and stop the flapper valve from seating properly; I'm hoping I can use the daily flushing from the iron filter to help keep this device clean so it works when it needs to. I would also put a P-trap in the backflush line as an extra precaution.

I'm hoping these precautions will keep the system sealed, provide a means of properly dumping the iron laden backflush water, and get the side benefit of helping to keep the main drain nice and clean.

Before heading down this path I've learned to ask you folks first. Hopefully someone out there's done something like this before and knows some tricks.

I'm really anxious to hear your thoughts.

Cheers
TY


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## AlbacoreShuffle (Aug 28, 2011)

Can you run the backflush to the laundry drain ?
If you can you could get an air gap and it should meet code.
We run softener drains to the laundry all the time.


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## Traderyoda (Aug 7, 2012)

AlbacoreShuffle - very tough - laundry's on the second floor and the house is insulated with foam insulation. The crawlspace has about 10 inches of foam everywhere... it looks like an igloo. Getting a line that far would be virtually impossible.


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## AlbacoreShuffle (Aug 28, 2011)

Traderyoda said:


> AlbacoreShuffle - very tough - laundry's on the second floor and the house is insulated with foam insulation. The crawlspace has about 10 inches of foam everywhere... it looks like an igloo. Getting a line that far would be virtually impossible.


Can you install a trapped drain on the first floor and run it to that ?


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## rjbphd (Feb 5, 2010)

I'd the unit in the closet and install sound proofing door for access to the unit... sure, u'll lose some space, but hell who designed this home that gonna have 'perfect' water... when I'm shown a drawing for new homes, I pushed for larger and more practical mech room over those freakin oversized hot tub that they rarely used after 6 months.


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## Mississippiplum (Sep 30, 2011)

How digging a dry well outside and terminating the backwash drain into that?

sent from the jobsite porta-potty


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## Traderyoda (Aug 7, 2012)

Mississippiplum - possible... but digging around here is anything but simple. This house is on the Chesapeake Bay and since it's waterfront the house is located in "the critical area" meaning no digging without a permit. Getting a permit is a prohibitively long process and doing it on the sly can get you slapped with a hefty fine. It would have to be a substantial hole since the iron will build up over time and the water table is just about 2-3 ft. underneath the lowest point the crawlspace, so you can't dig very far.


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## Mississippiplum (Sep 30, 2011)

Is the job permitted?

sent from the jobsite porta-potty


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## rjbphd (Feb 5, 2010)

Traderyoda said:


> Mississippiplum - possible... but digging around here is anything but simple. This house is on the Chesapeake Bay and since it's waterfront the house is located in "the critical area" meaning no digging without a permit. Getting a permit is a prohibitively long process and doing it on the sly can get you slapped with a hefty fine. It would have to be a substantial hole since the iron will build up over time and the water table is just about 2-3 ft. underneath the lowest point the crawlspace, so you can't dig very far.


 Back into the closet...


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## Mississippiplum (Sep 30, 2011)

Sounds like the best way is to drill through that foam and run the line to the laundry sink or standpipe

sent from the jobsite porta-potty


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## Traderyoda (Aug 7, 2012)

Yep - I have a trades permit for the installation, but no permit for mods outside the house (digging, etc.).

I can get through the foam okay, but finding and snaking a line to the second floor would be a major nightmare.

Another problem with running the line upstairs to the laundry drain is noise. This is a fairly high flowrate and it typically happens at night when no other water is moving around. The foam insulation keeps any noises in the crawlspace far away from the house (you can't hear the pressure tank, for example).

The sewer is appealing also because it exits the crawlspace right beside the entry point for the well - the pressure tank is sitting close by and there's power available to run the iron filter timer.


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## rjbphd (Feb 5, 2010)

Traderyoda said:


> Yep - I have a trades permit for the installation, but no permit for mods outside the house (digging, etc.).
> 
> I can get through the foam okay, but finding and snaking a line to the second floor would be a major nightmare.
> 
> ...


 Sewer pipe next to well entry point??? That's not code here..


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## Traderyoda (Aug 7, 2012)

Well... the inflow from the well is 1" poly tube that comes up in the foundation - it's properly secured and then feeds into a 65 gal. pressure tank. The main sewer drain runs the length of the house and exits through the cinderblock wall in the crawlspace. It turns and exits pretty close (about 6 feet) to the pressure tank. This installation is very well done and passed code here w/o a hitch. My job is to install the iron filter downstream of the pressure tank, so if I use the sewer line it's pretty close by. By the way, a sewer backflow device is not required by code in this area; I've heard they're becoming a requirement in a lot of places.


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## reedplumber (Sep 25, 2012)

I'd say code or not better safe than sorry, if the city jets routinely I'd put one in, when they jet around here though it has been known to suck a trap or two dry. That may create a little stitch under there though.


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