Iron in deep well water

[Chris1975]

I have a deep well which I pump water from into large water tanks via a hose.
 

I then use the water from these tanks with a automatic pump to feed water into the house for day to day use….. 

 

The problem I have is that there is significant iron in the water. 
 

The water runs “clear” from the well/hose but when the water has sat for a while it goes a rusty colour and also smells of metal. 
 

Any ideas how I can fix this?

 

 

[Bill97]

From the well the water needs to be aerated then run through a filter. That worked in two location for me.

[sometimewoodworker]

Use one of these first, common to see in some areas 

Edited October 16, 2022 by sometimewoodworker

[Greenside]

 

It depends on just what you mean by "sit for a while". Ten years of trying different approaches tells me that if it's anything shorter than a couple of hours you are unlikely to be able to clear this water to a state where you will want to use it in your house.  After the first year we switched to city water which (luckily) had just become available and just run the well water through an aerator and two serious filter units for irrigation - even then, pipes, sprinkler heads and valves clog up quickly and need lots of maintenance.  If you can, switch your supply: it's likely to be cheaper in the long run.

[carlyai]

Well here's my take.

We had what looked like nice clear water from our well into our 3000 L tank.

I noticed that the bathroom shower tiles were turning a rusty color, so decided to investigate the water. 

Short story is you need to get your water professionally tested at the Amphur. 

(My theory):  The iron is in the water, but it doesn't oxidise until the water mixes with the air  so then the iron precipitates out and gives that rusty look.

Once you get your water analysed you will know what filtets to install to filter out all the iron etc. 

So my aquifer water goes into a 3000L settlement tank, then to 2 big backwashable filtets in series. One filter has active carbon and the other crushed plate glass. From there it goes to a Big Blue sediment filter ....from there (for the drinking water) to a 6 stage reverse osmosis filter.

All this came about from rusty looking tiles and water analysis.

6 L of water and about B6000 is what Khon Kean university charge for detailed water analysis 5 or 6 years ago.

[unheard]

@Chris1975

You need to run a lab water test.

 

This particular test includes:

pH, Turbidity, Color, Total Hardness, Chloride, Total Iron, Manganese, Nitrate, Sulfate, Total Dissolved Solids, Arsenic, Cadmium, Copper, Lead, Mercury, Selenium, Zinc, Cyanide, Fluoride, Non Carbonate Hardness, Standard Plate Count, Coliform Bacteria, E. coli

 

https://www.testtech.co.th/th

[Liverpool Lou]

If the water is clear/clean when it comes from the well but dirty/rusty when it leaves your tanks, perhaps you just need new tanks/piping?

[carlyai]

15 hours ago, Liverpool Lou said:

If the water is clear/clean when it comes from the well but dirty/rusty when it leaves your tanks, perhaps you just need new tanks/piping?

For me, no, as the tank is SS, pipes PVC and filter bodies fiberglass and cloth. ????

[Muhendis]

28 minutes ago, carlyai said:

For me, no, as the tank is SS, pipes PVC and filter bodies fiberglass and cloth. ????

Absolutely right. No need to take such drastic measures.

As has been said. Aerate the water.

This will cause iron to become oxidised and become "lumpy" enough to be filtered out.

Another way is to purchase an O3 (ozone) generatorwhich does the same as an aerator but much quicker.

[Saanim]

The various aeration systems you can see in many villages where they have problems with iron in water. And you can see that the tanks and everywhere around are rusty anyway. Usually, there is a concrete ring tank with sand inside, placed onto two concrete storage tanks where the filtered water should flow in and get stored.

 

The problem is that the sand will be very soon clogged by the fine rust and the water does not go through the sand but over the edge of the tank.

 

An easy solution is (as it had worked for me with very strong ironized water): As you wrote you have got large tanks, not just one.  You can store the fresh water in one tank, keep it there for 2 -3 days to oxidate (whether with or w/o aerator) and to sediment. The oxidation process can be sped up by addition of chlorine. The rust will sediment well to the bottom, only then the clear water can be taken few cm above the bottom.  

 

In the meantime of the sedimentation in one tank you use the water from the other tank(s) where the sedimentation has been processed before. Hence, the levels in the tanks are to be supervised every day and once empty the intake to be switched over to the other tank. (and when empty to fill it up again, etc.) Any try to make it as a continuous process will fail, even with very large tanks and with some kind of labyrinth between the inlet water and the outlet.  About that I could write stories with enclosed rusty and muddy pictures.

 

The long storage and sedimentation does not fully remove the iron from the water (if a strong iron content), there are also some other metals (manganins) needing a longer oxidation. Therefore, the clear water after a proper sedimentation should be led through a filtering system that is possible to be timely backwashed.  Then, such water you can use for drinking (after a further filtering) and also for a swimming pool.

 

And of course, the sedimentation tanks are to be drained and cleaned after few months. For that a really large drain outlet is advisable, with a proper slope. The remaining rust sediment is pretty heavy and does not flow out easily.

 

   

 

 

 

 

[Saanim]

23 hours ago, Liverpool Lou said:

If the water is clear/clean when it comes from the well but dirty/rusty when it leaves your tanks, perhaps you just need new tanks/piping?

Of course the water from the well comes very clear/clean, it has not got oxidised yet. Give it a chance for a while...

[Lacessit]

Ferrous iron in solution is very faint green in color, ferric iron is orange going to dark brown.

The first thing I would do is get the iron content of the water measured. A simple job for any laboratory with an atomic absorption spectrometer.

Depending on the content, the OP could elect to remove the iron with an ion exchange system. The other option would be oxidizing the iron using hydrogen peroxide, then flocculating it out by adjusting the pH upwards with lime. My guess would be the well water has a pH < 7. If he wants to gild the lily, add some diatomaceous earth as well.

I would certainly get the water tested for heavy metal pollution. The presence of iron in solution is not a good sign.

Iron is quite toxic, especially when ingested by children.