High Iron and maybe Arsenic well water treatment

[Nate Schwartz]

Hi all! Thank you so much for this amazing forum. The wealth of knowledge here is incredible and greatly appreciated. I hope you can help me with a little guidance on water treatment at a recently purchased home. The house came with an owned Culligan water softener and Super S system installed. I cannot be 100% certain, but am relatively sure they were installed right around the time the place was built in 1995....so about 25 years old or so. Based solely on that I would assume they are due for upgrade/replacement or at the least a rebed.

As part of the purchase we had a basic water test done. Nothing too crazy except Arsenic was detected. The home inspector took the sample from the pressure tank and it came back at 10.4ppm. Based on that we were super concerned so we had a second test done, but this sample was taken from the kitchen sink. This one was done by the Wisconsin state lab and came back as not detected. The home also has an RO system so we primarily just use that for cooking/drinking. I decided to get a comprehensive water analysis done and have taken new samples, from the pressure tank again, so I know what is exactly in my water. Those tests are pending and I will hopefully have them soon.

Additionally, we have noticed very high iron in our water. Everything is staining orange. The sediment pre-filter we have becomes caked with orange sludge after a very short time and the whole utility room has rust stains from splashed water. Basically my questions is what route should I look at taking. I know we need the full results to make an exact decision, but any suggestions on initial research I should look at.

The house is a 4 bedroom 6 bathroom, but only 4 people (2 adults, 2 kids). I tested the well pump and it looks like I get about 9gpm. The earlier test results I do have are:

pH 7.3
Iron 5ppm
Hardness 17gpg
Aresnic Maybe 10.4 maybe zero :/

I really appreciate any direction at this point. The more I read the more confused I seem to become. Thank you all!

Nate

 

[Water Pro]

arsenic 3, or arsenic 5?

 

[Sponsor]

 

[Nate Schwartz]

arsenic 3, or arsenic 5?

Unfortunately the home inspectors test did not differentiate. I just got a total arsenic reported. And since the repeat from the tap came back not detected that didn't help either. Assuming it comes back positive, the lab will speciate it for me.

 

[EAJ]

Redacted

 

[Reach4]

arsenic 3, or arsenic 5?

Do your water tests report those numbers separately?

I was pleased, and surprised, that my iron+H2S filter reduced my arsenic below the test detection level. My arsenic in the raw water tested at 0.006. I only noticed arsenic by doing comparisons of the raw and post-filter tests. I did those tests when KAR Laboratories was still offering those great $60 lab water tests.

 

[ditttohead]

Katalox Lite has been reportedly effective in arsenic reduction, along with iron filtration, but I'm not certain what form of arsenic.

Katalox light does not remove Arsenic. Katalox light can be used in conjunction with ferric iron for the coprecipitation of arsenic onto the iron for arsenic reduction. Please be extremely careful making recommendations about a treatment method especially a dangerous contaminant like arsenic if you are not sure. Making a recommendation like that is not helpful and can be harmful.

 

[ditttohead]

Once we see the whole water report we can make a better recommendation, otherwise we are just pontificating. Iron reduction with oxidant injection to assist with iron removal and making the arsenic 3 to 5 for easier and more consistent reduction. You may have reduced arsenic in the house due to the high iron, coprecipitation may be occurring in your existing equipment... hard to say for sure. Use the iron reduction system to coprecipitate some f the arsenic, but use a secondary arsenic specific media for redundancy and near complete removal, then a simple softener to make the water a little nicer. Lets see the water report so we can make a real recommendation.

 

[Nate Schwartz]

Thanks guys. The water test that the home inspector did did not report the type of arsenic at all....just total. I will know soon for sure though.

I thought I had seen that katalox light did do something with aresnic. That is interesting. I swear the companies website even said it. Regardless, I totally agree I need all the numbers before I can get anything definitive, I am just trying to do as much research now as possible so I have a clue what to order when the numbers do come back. I just don't really understand when you want air injection vs. chlorine injection and this media vs that. I appreciate all the advice and info. Thanks guys!

 

[Reach4]

I thought I had seen that katalox light did do something with aresnic.

It does.

https://www.watchwater.de/wp-content/uploads/2019/01/KATALOX-LIGHT-General-Brochure.pdf

However it is not a simple yes/no. See https://www.watchwater.de/wp-content/uploads/2019/01/Katalox-Light-removal.pdf page 6.

 

[ditttohead]

Gotta love the German to English translations... Katalox light itself does not remove arsenic.

When iron removal is needed as a pre-treatment to an arsenic filter, KL is a good choice as an iron removal media as it can convert trivalent arsenic to pentavalent arsenic to enhance removal at subsequent treatment stages. The iron level must be a minimum of 20 times the arsenic level, indirect removal of arsenic is also likely through adsorption to the ferric hydroxide particles created during iron removal (co-precipitation).

 

[Nate Schwartz]

Great info and reading material. Thank you! It makes some sense lol

 

[Water Pro]

View attachment 69146

Gotta love the German to English translations... Katalox light itself does not remove arsenic.

When iron removal is needed as a pre-treatment to an arsenic filter, KL is a good choice as an iron removal media as it can convert trivalent arsenic to pentavalent arsenic to enhance removal at subsequent treatment stages. The iron level must be a minimum of 20 times the arsenic level, indirect removal of arsenic is also likely through adsorption to the ferric hydroxide particles created during iron removal (co-precipitation).

no it good at chemistry? could have fooled me. lol

 

[Nate Schwartz]

Ok Guys! So the results are in.

• Nitrate ND
• NO3 ND
• Nitrite ND
• Flouride 0.0925 mg/L
• Aluminum ND
• Aresnic ND - That is two negative tests which leads me to believe the home inspectors test was a contaminant or lab error
• Cadmium ND
• Calcium 60.1 mg/L
• Chromium ND
• Cobalt ND
• Copper 10.1 ug/L
• Iron 7.75 mg/L - This seems pretty high but not surprised based on the color of my water
• Lead ND
• Magnesium 32.3 mg/L
• Manganese 90.7 ug/L
• Nickel ND
• Strontium 38.1 ug/L
• Vanadium ND
• Zinc 24.3 ug/L
• Hardness 283mg/L
• pH 7.5
• Total Coliform Absent
• E-Coli Absent

So based on those numbers what would you all recommend I go with. I really appreciate the insight. Thanks all!

 

[ditttohead]

The high iron should be treated properly to help minimize service problems and maintenance issues. H202 or chlorine injection with a contact tank (baffled preferred) with a simple blowdown and a iron reduction media tank and/or a Carbon tank followed by a softener would likely be a good solution. Many companies will push lower cost solutions but these can be a lot more troublesome due to the high iron levels. Also, these iron levels are what you have today, it is unlikely these numbers will stay the same, they will fluctuate up and down over time.