Looking for ideas: Backwash from water treatment system

[user 31216]

Does anyone have a good solution for handling the backwash outflow from a water treatment system that removes iron from the water? The primary issue is the outflow contains iron oxide particulate and that ends up becoming a goopy rusty mess in the bottom of the reservoir and eventually hinders sufficient draining of the reservoir into the ground. (If you wish, you can read details of my backwash saga at bottom). I'm sure I'm not the only one with this issue and there must be some better way to address this goo that builds up.

Backwash Saga
We're on a well that flows 7.5 gpm, with a static column about 200 ft. The water has 14ppm iron (otherwise clean) and the water treatment system uses H2O2 and a resin tank followed by two filters that does a good job of oxidizing out the iron and keeping the water clean. The resin tank is on a double backwash cycle at 2am.

We moved in four years ago and at that time, the backwash outflow was routed through a 50 ft french drain buried in the ground. Maybe a year after we moved in, it became clear that the current backwash situation wasn't sufficient -- I think the french drain had just gotten clogged with the oxide goo, dirt, roots, etc. So, I routed the outflow to a 100 gal reservoir I made out of a couple of large bins. I dug a whole, put in 6" of gravel, and put the bins upside down over the gravel. The idea is that the reservoir would be a temporary holding tank to accept the outflow faster than it might be able to drain, and allow the water to drain into the ground over the next 24 hours before the next backwash cycle.

This worked fine until last year when I again began having issues due to insufficient backwash outflow. When I investigated, I could tell that this reservoir just wasn't sufficient. So, I pulled that out dug out the pit deeper so I could put in a 250 gal tank (see photo), cut the bottom out of it, and set it on the gravel. Again, the idea being that this would be a temporary receptacle to accept the outflow as fast as it comes and then allow sufficient draining over the next 24 hours. This is still working but I can tell the goo is building up and I'm concerned about it inhibiting draining of the water into the ground.

 

[Twowaxhack]

The problem with burying unapproved tanks is that kids playing have caved them in when they get old and have drowned.

I’ve had people give many excuses and reasons why this could never happen because of……fill in the blank.

But the facts are we are not guaranteed tomorrow so we might be dead and someone else moves into the property with a death trap set up for their 3 yr old to drown in.

 

[user 31216]

The problem with burying unapproved tanks is that kids playing have caved them in when they get old and have drowned.

I’ve had people give many excuses and reasons why this could never happen because of……fill in the blank.

But the facts are we are not guaranteed tomorrow so we might be dead and someone else moves into the property with a death trap set up for their 3 yr old to drown in.

Providing a negative response with no other recommended solution is not helpful.

 

[Twowaxhack]

Providing a negative response with no other recommended solution is not helpful

Ignorance can’t be your excuse now. Do as you please.

I recommend digging up your plastic tanks and installing enough field line to absorb the water.

The answer is simple.

 

[MicEd69]

Providing a negative response with no other recommended solution is not helpful.

Let me apologize for Twowaxhack. He has a wealth of knowledge, but his bedside manner is a little rough sometimes. He often responds emotionally first without offering suggestions on a solution. But he is quite knowledgeable on plumbing related issues.

Your thought process has some logic to it, but I'm afraid you don't understand soil mechanics as it relates to absorption of materials.

As you are on a well, you also may be on a septic system. In any case, a septic system takes wastes from your house and collects it in a septic tank where aerobic bacteria break down the wastes. Liquid wastewater flows out of the septic tank into a drain or leaching field. The drain field is a network of underground perforated pipes where the liquid wastes percolate down into the soil. There are always a little solids in the liquid, so after several years, say 50, the septic drain field becomes "blinded" and the liquid will not percolate into the soil at a fast enough rate, and liquid wastes starts puddling on the surface.

That is what is happening to the area where you are draining your backwash. So, the answer is not adding surge for the backwash, but it is to add additional drainage area for the backwash.

 

[Twowaxhack]

Let me apologize for Twowaxhack. He has a wealth of knowledge, but his bedside manner is a little rough sometimes. He often responds emotionally first without offering suggestions on a solution. But he is quite knowledgeable on plumbing related issues.

Your thought process has some logic to it, but I'm afraid you don't understand soil mechanics as it relates to absorption of materials.

As you are on a well, you also may be on a septic system. In any case, a septic system takes wastes from your house and collects it in a septic tank where aerobic bacteria break down the wastes. Liquid wastewater flows out of the septic tank into a drain or leaching field. The drain field is a network of underground perforated pipes where the liquid wastes percolate down into the soil. There are always a little solids in the liquid, so after several years, say 50, the septic drain field becomes "blinded" and the liquid will not percolate into the soil at a fast enough rate, and liquid wastes starts puddling on the surface.

That is what is happening to the area where you are draining your backwash. So, the answer is not adding surge for the backwash, but it is to add additional drainage area for the backwash.

Mind your business. You’re not my keeper.

 

[Twowaxhack]

Every time I take out a plumbing permit, no matter the reason, I’m required to sign a separate notation on the permit form requiring me to pump fill with dirt all vaults or tanks found on the property that are not approved or are discontinued.

These posts, like my signature is so a negligent person can’t claim ignorance when a tragedy happens. Now it’s not ignorance it’s called negligence.

So I’m grateful that the OP acknowledged my post, it confirms he read it. I’ve done my job.

I hope everyone is having a wonderful Easter Sunday.

https://njaes.rutgers.edu/fs516/

 

[MicEd69]

Mind your business. You’re not my keeper.

Just educating and providing information to a new poster Twowaxhack.

When I posted my first question here, you also responded with a negative response that was actually not even factual. And there have been several new posters that have said similar things in response to your initial response to them as IronRod said here; i.e. not answering their question but providing a rather snide remark. I wanted IronRod to know you have a wealth of knowledge, you just don't always provide it until it is asked a second time and often do not explain things so the poster can understand your reasons for the answer you give.

And I would NEVER accept being your keeper, and I know you would NEVER accept me attempting to "keep" you.

 

[Twowaxhack]

Just educating and providing information to a new poster Twowaxhack.

When I posted my first question here, you also responded with a negative response that was actually not even factual. And there have been several new posters that have said similar things in response to your initial response to them as IronRod said here; i.e. not answering their question but providing a rather snide remark. I wanted IronRod to know you have a wealth of knowledge, you just don't always provide it until it is asked a second time and often do not explain things so the poster can understand your reasons for the answer you give.

And I would NEVER accept being your keeper, and I know you would NEVER accept me attempting to "keep" you.

Just shut up man……I’m not the subject of this forum.

 

[Mitchell-DIY-Guy]

 

[Mitchell-DIY-Guy]

I had what they call a "chem free" iron filter at my second home in Michigan; it used some kind of aerator to turn dissolved iron into undissolved iron, and then a gravel-filled tank to filter out the now undissolved iron. It too, went through a backwash procedure in the middle of the night. I don't recall this being every day, but maybe a few times a week. I also don't recall that the backwash was so much water, not more than doing laundry and a shower or whatever. I never saw the effluent as it went right into a drain pipe in the crawl space and out to the tank/drainfield. Many of the homes in that area had the same setup. The only issue I ever had was cracks in certain pipes near the tank which my septic guy could fix relatively quickly, easily and for just a couple of hundred dollars.

Probably sounds like a good idea to have it drain outside the septic system, such as the French drain system you inherited. But if that drain, your drywell (with the encaged poly tank) and or your drain field cannot handle water drainage from your normal life and the iron filter, maybe your property needs another perc(elation) test.

Sadly none of this stuff (any kind of repair or extension or whatever) comes cheap. In Michigan with that sandy soil we had maybe 40' of drain field. In the clay soil of NC, a similar home would require hundreds of feet of double stack T&J panels as they call them, installed in 36" deep trenches. Massive work and the panels aren't exactly inexpensive. Typical home around here costs $20K for septic.

Probably your best source to help solve the problem is not the internet and not here, but local contractors experienced in drain field work. Check with your neighbors and or the AHJ which may mean the city, town or county depending...