Hexavalent Chromium and Nitrate Removal with Anion Exchange

[UnlimitydAl]

We would like to remove hexavalent chromium and nitrates at the whole-house level in addition to other contaminants. We're planning on a whole house filter, probably the Radiant Life Series 4, as well as a cation softener (to remove radium), currently leaning towards Fleck 5600 Econominder. We want to use potassium chloride instead of sodium.

It's our understanding that we need an anion exchange set up to reduce the hexavalent chromium. However, we're having trouble finding such a setup. What have you all done? What DIY options exist? Is DIY not the way to go with something like this? If so, what professionally installed options are there?

Is it as easy as removing some of the resin in the Fleck or similar cation softener and replacing some of it with anion resin? Is it better to have a completely separate anion tank?

Does anion exchange work just fine with potassium chloride?

Any recommendations or dos/don'ts for the DIYer with this setup?

These are the contaminants we would like to remove at the whole-house level:
Total trihalomethanes (TTHMs) - handled by the radiant life filter
Radium, combined (-226 & -228) - cation softener
Lead- handled by the radiant life filter
Chromium (hexavalent) - anion exchange
Chlorate (assuming there is no possible removal method for this)
Nitrate - anion exchange
Haloacetic acids (HAA5) - handled by the radiant life filter
Copper - handled by the radiant life filter
Fluoride - handled by the radiant life filter

 

[ditttohead]

http://watercheck.myshopify.com?aff=5

Without a complete lab test, it is really hard to say what treatment options make the most sense.

After reading through the literature, I would really use a lot of caution when purchasing from companies online.

When it comes to using Anion resins, do you understand the side affects of these medias?

Please post a real laboratory water test otherwise we are only wild guessing what treatment methods would work for you. Just a simple side note, fluoride reduction is far more difficult than most companies realize. There are no secret medias that only one person knows about. Fluoride reduction methods are expensive, only marginally effective and require monitoring and constant re-bedding. The fact that very few people ever tests the before and after results nor do they monitor it shows me that most people are fooled by the marketing.

 

[Sponsor]

 

[UnlimitydAl]

Those are the contaminants as reported by our water utility. Here is their full listing. We want to stay under the EWG guidelines as we have health issues in our family.

Total trihalomethanes (TTHMs) = 96.8 ppb
Radium, combined (-226 & -228) = 1.9 pCi/L
Lead = 2.6 ppb
Chromium (hexavalent) = 0.0482 ppb
Chlorate = 360.1 ppb
Nitrate = 0.14 ppm
Haloacetic acids (HAA5) = 40.17 ppb
Copper = 0.18 ppm
Fluoride = 0.31 ppm
Strontium = 198.7 ppb
1,4-Dioxane = 0.0323 ppb
Manganese = 2.3 ppb
Barium = 12 ppb
cis-1,2-Dichloroethylene = 0.86 ppb
Dalapon = 1.8 ppb
Chromium (total) = 0.65 ppb
Vanadium = 0.0875 ppb
Chlorine = 1.58 ppm
Hardness = 7 grains
Sodium = 33 ppm

 

[Reach4]

Nitrate = 0.14 ppm

MCL (maximum contaminate level) is 1.00 -- over 7x the number in the water report that you cite. ppm https://www.wqa.org/Portals/0/Technical/Technical Fact Sheets/2014_NitrateNitrite.pdf

Chromium (total) = 0.65 ppb

As far as I have found, In California the MCL for Chromium 6 was 10.00 ppb for a while, and is now up to 50.00 ppb. Even the 10 ppb number is over 200 times the number in your report.

Could you have gotten ppm and ppb confused? It would seem a shame to invest in extraordinary filtering for your bath water. A good point-of use RO filter, perhaps feeding the fridge through a plastic pipe, would let your drinking water be way more pure than anybody requires. So that would be caution at a reasonable price (or footprint if you prefer).

Yes, RO takes water, but there are some "zero waste" ROs that put that otherwise-wasted water back into the hot water supply.

A backwashing filter takes significant water for backwashing too.

 

[Bannerman]

In response to your question on what we have 'all done', many here utilize reverse osmosis systems for drinking and cooking.

To remove chlorine, THMs, chemicals and other contaminates which may be breathed in or absorbed through skin while bathing, some here utilize backwashing carbon filtration systems located at point of entry.

 

[UnlimitydAl]

MCL (maximum contaminate level) is 1.00 -- over 7x the number in the water report that you cite. ppm https://www.wqa.org/Portals/0/Technical/Technical Fact Sheets/2014_NitrateNitrite.pdf

As far as I have found, In California the MCL for Chromium 6 was 10.00 ppb for a while, and is now up to 50.00 ppb. Even the 10 ppb number is over 200 times the number in your report.

Could you have gotten ppm and ppb confused? It would seem a shame to invest in extraordinary filtering for your bath water. A good point-of use RO filter, perhaps feeding the fridge through a plastic pipe, would let your drinking water be way more pure than anybody requires. So that would be caution at a reasonable price (or footprint if you prefer).

Yes, RO takes water, but there are some "zero waste" ROs that put that otherwise-wasted water back into the hot water supply.

A backwashing filter takes significant water for backwashing too.

Thank you for your response!

We're not so much concerned with being under legal limits but want to be under optimal limits as our family has liver disease concerns and family history of cancer. We understand that the reported levels are not nearly as bad as some have had to deal with, thankfully.

California actually has a public health goal of 0.2 ppb for hexavalent chromium. https://oehha.ca.gov/media/downloads/water/chemicals/phg/cr6phg072911.pdf

EWG recommends less than 0.14 ppm for Nitrates. https://www.ewg.org/tapwater/reviewed-nitrate.php

However, regardless of these levels and limits, the goal of our post was to try to get information on how we would accomplish this type of contaminant reduction to then see if it's feasible for us to do. We know we can do the whole house filtration and softener fairly simply, but what we don't know as much about is anion exchange and was hoping to learn. Would some form of anion exchange tank or hybrid with the cation work? How does one accomplish this? What's the best approach? Thanks so much!

 

[UnlimitydAl]

In response to your question on what we have 'all done', many here utilize reverse osmosis systems for drinking and cooking.

To remove chlorine, THMs, chemicals and other contaminates which may be breathed in or absorbed through skin while bathing, some here utilize backwashing carbon filtration systems located at point of entry.

Thank you. Yes, we do plan to put in a point of use reverse osmosis at the sink. However, that doesn't help with getting clean water to the refrigerator for ice as our plumbing and line to the fridge is not accessible from the sink. It also doesn't help with teeth brushing and bathing.

 

[Reach4]

California actually has a public health goal of 0.2 ppb for hexavalent chromium.

That is 4x the number you posted.

I understand that you are on a slab, so new tubing would have to run through the attic.

 

[Bannerman]

The feed between the RO unit to the refridgerator will be single 1/4" or 3/8" flexible polyethylene tube. The existing water feed could be simply disconnected and capped so the RO poly tubing can be similarly connected to the fridge. We recently replaced our 30 yo fridge with one with an ice & water dispenser. I teed off the RO counter mount faucet. No issues and is working well.

With regard to brushing teeth, that water should not be ingested regardless. We typically perform a final rinse with fresh RO water from a glass.

According to the literature, the Radiant Life 4 system you are considering, contains carbon filter media and some Zeolite media. I have not found where they indicate the quantity of each media, only the total volume of all media in each tank. While back washing has been proven beneficial for carbon and Zeolite media, it seems only the 3 & 4 ft3 units are equipped with Clack back washing heads whereas the 2 ft3 unit has only an In/Out head.

Because RL claim series 4 will remove Chloramines, I anticipate each size is equipped with Catalytic Carbon which is more effective than standard granular activated carbon for Chloramine reduction.

The quantity of each media is important as the water must have adequate contact time with the media for contaminates to be adsorbed by the media. Carbon will be most effective for contaminate removal when the flow rate is between 1-3 gpm per ft3 of media so with a 3 ft3 system, 3-9 gpm. A flow range is specified as contaminates adsorb at different rates, some requiring longer contact duration than others. While Zeolite will also have an effective service flow rate, if the quantity of Zeolite is minimal, then there may be an inadequate quantity of the media to provide much benefit, especially when water is being drawn at the usual flow rate. The 27 gpm maximum flow rate stated, will provide minimal contaminate reduction from either media.

Since many filtration medias weigh differently, heavy media will settle to the bottom of the tank, often where it will not be the most effective. Also, heavy media typically requires a different back wash rate than a light weight media. Unless the medias are proven compatable, different media should usually not be mixed together in the same tank even though some suppliers continue to do so.

 

[UnlimitydAl]

That is 4x the number you posted.

I understand that you are on a slab, so new tubing would have to run through the attic.

I am so sorry. I mistyped. Their recommendation is 0.02 ppb. It's the first sentence of the link I posted above.

 

[UnlimitydAl]

The feed between the RO unit to the refridgerator will be single 1/4" or 3/8" flexible polyethylene tube. The existing water feed could be simply disconnected and capped so the RO poly tubing can be similarly connected to the fridge. We recently replaced our 30 yo fridge with one with an ice & water dispenser. I teed off the RO counter mount faucet. No issues and is working well.

With regard to brushing teeth, that water should not be ingested regardless. We typically perform a final rinse with fresh RO water from a glass.

According to the literature, the Radiant Life 4 system you are considering, contains carbon filter media and some Zeolite media. I have not found where they indicate the quantity of each media, only the total volume of all media in each tank. While back washing has been proven beneficial for carbon and Zeolite media, it seems only the 3 & 4 ft3 units are equipped with Clack back washing heads whereas the 2 ft3 unit has only an In/Out head.

Because RL claim series 4 will remove Chloramines, I anticipate each size is equipped with Catalytic Carbon which is more effective than standard granular activated carbon for Chloramine reduction.

The quantity of each media is important as the water must have adequate contact time with the media for contaminates to be adsorbed by the media. Carbon will be most effective for contaminate removal when the flow rate is between 1-3 gpm per ft3 of media so with a 3 ft3 system, 3-9 gpm. A flow range is specified as contaminates adsorb at different rates, some requiring longer contact duration than others. While Zeolite will also have an effective service flow rate, if the quantity of Zeolite is minimal, then there may be an inadequate quantity of the media to provide much benefit, especially when water is being drawn at the usual flow rate. The 27 gpm maximum flow rate stated, will provide minimal contaminate reduction from either media.

Since many filtration medias weigh differently, heavy media will settle to the bottom of the tank, often where it will not be the most effective. Also, heavy media typically requires a different back wash rate than a light weight media. Unless the medias are proven compatable, different media should usually not be mixed together in the same tank even though some suppliers continue to do so.

Thank you for such detailed information! I've emailed the person I've been communicating with at Radiant Life and have asked for more details on the media.

We just did a complete kitchen remodel and found that the house was previously replumbed and the water line to the refrigerator does not come from the sink area. Since we just had the kitchen remodeled, we really really didn't want to go down the road of tearing it up and potentially damaging the new cabinets.

Should I assume from all the responses that an anion exchange system at the whole-house level is just not possible? Or is it that it is not effective?

 

[Bannerman]

I ran my poly tubing from the RO faucet, along the rear of each cabinet before exiting at the rear of the cabinet adjacent to the fridge location. It was easy, inconspicuous and required no removal of cabinets. Even as it will remain virtually invisible unless the fridge is pulled out, if you don't wish a hole through the end cabinet gable, there may be enough gap between the counter top and the cabinet as filler pieces between the two will often have spaces between them. Alternately, drill a small groove in the drywall directly behind the cabinet gable, just large enough to allow the tubing to slide behind the gable. If the tube is later removed, the drywall may be easily patched and painted.

With regard to anion water, when combined with softened water, is commonly referred to as deionized water. While DI water is often used for spotless vehicle rinsing and in conjunction with an RO system for salt water aquariums, I am not aware of anyone consuming it or using it throughout their home.

As Ditttohead mentioned side effects, because your concerns are mainly heath related, I would think you would not wish to implement a water treatment method that has known risks or issues compared to the system it is to replace.

I anticipate a common PoU RO system will either eliminate or at least substantially reduce the elements in the water you are most concerned with ingesting while a back washing carbon system could reduce/eliminate most of the skin absorption concerns. Because RO will remove sodium, I anticipate your concern with using potassium chloride to reduce sodium intake, might also be eliminated.

 

[Reach4]

I ran my poly tubing from the RO faucet, along the rear of each cabinet before exiting at the rear of the cabinet adjacent to the fridge location.

If the sink was on a different wall, that could make it harder. How about some crown molding hiding the tubing?

 

[Bannerman]

If the sink was on a different wall, that could make it harder.

True, we only know as much as we are told. Perhaps the sink is located in an island in which case, there would be no connected walls to install crown molding, making the situation more difficult still.

Relating a previous experience or offering a suggestion, will not always be relevant, but may provide an option that might be suitable which the OP may not have considered.

 

[ditttohead]

An anion system would not be recommended for your application. If you want to do it right and certified, the Pioneer system by Enpress may be a good option for you. This particular filter is certified for the reduction of chlorine, chloramine, lead, PFOS, and PFAS. For your drinking water, a simple high quality and NSF certified RO would be ideal. Does your refrigerator have any breaks between the kitchen sink and the refrigerator? Doorways, or is your kitchen sink on an island. If not, then you can simply drill some holes in the back of the cabinets and run the 3/8" line from the RO to the refrigerator.

 

[Reach4]

You could have a second RO in the bathroom if you had spare space you were willing to give up.

 

[UnlimitydAl]

The feed between the RO unit to the refridgerator will be single 1/4" or 3/8" flexible polyethylene tube. The existing water feed could be simply disconnected and capped so the RO poly tubing can be similarly connected to the fridge. We recently replaced our 30 yo fridge with one with an ice & water dispenser. I teed off the RO counter mount faucet. No issues and is working well.

With regard to brushing teeth, that water should not be ingested regardless. We typically perform a final rinse with fresh RO water from a glass.

According to the literature, the Radiant Life 4 system you are considering, contains carbon filter media and some Zeolite media. I have not found where they indicate the quantity of each media, only the total volume of all media in each tank. While back washing has been proven beneficial for carbon and Zeolite media, it seems only the 3 & 4 ft3 units are equipped with Clack back washing heads whereas the 2 ft3 unit has only an In/Out head.

Because RL claim series 4 will remove Chloramines, I anticipate each size is equipped with Catalytic Carbon which is more effective than standard granular activated carbon for Chloramine reduction.

The quantity of each media is important as the water must have adequate contact time with the media for contaminates to be adsorbed by the media. Carbon will be most effective for contaminate removal when the flow rate is between 1-3 gpm per ft3 of media so with a 3 ft3 system, 3-9 gpm. A flow range is specified as contaminates adsorb at different rates, some requiring longer contact duration than others. While Zeolite will also have an effective service flow rate, if the quantity of Zeolite is minimal, then there may be an inadequate quantity of the media to provide much benefit, especially when water is being drawn at the usual flow rate. The 27 gpm maximum flow rate stated, will provide minimal contaminate reduction from either media.

Since many filtration medias weigh differently, heavy media will settle to the bottom of the tank, often where it will not be the most effective. Also, heavy media typically requires a different back wash rate than a light weight media. Unless the medias are proven compatable, different media should usually not be mixed together in the same tank even though some suppliers continue to do so.

Here is their response on what media is in the filter. Any thoughts on this?

"Radiant Life Whole House Water Filtration Systems utilize a proprietary blend of Granular Activated Carbon (GAC) along with specialized media to improve the water making it better tasting and significantly reducing if not eliminating many contaminants. Our proprietary blend includes coconut shell carbon, catalytic coconut carbon and a bituminous coal carbon to address chlorine, chloramines, trihalomethanes, haloacetic acids, fluoride, heavy metals and VOCs including herbicides, pesticides, industrial solvents, pharmaceuticals, PFOA, PFOS, and EDCs among other contaminants before they enter your home’s plumbing while retaining essential minerals."

 

[UnlimitydAl]

You all got us thinking on the RO to refrigerator dilemma! Sometimes it helps to hear others and take a step back. It occurred to me that the kick plate panels under our cabinets are actually removable! Our sink is on a different wall than our refrigerator, but in an L shape. So, we could snake the water line from under the sink by drilling a small hole in the bottom of the cabinet under the sink, dropping the line to the ground, snake it under the cabinets along the L on the floor, drill a small hole in the back of the panel separating the cabinets and the refrigerator to get to the back of the refrigerator. We would have to cap off or disconnect the current water line and connect this new one. That should work!

I feel more comfortable about not addressing the hexavalent chromium and nitrates at the whole-house level if we can at least address them in the refrigerator.

So, now to ensure we're picking the right whole house units, I posted above Radiant Life's response to what type of media is in their filter. Thoughts on that?

Is the Fleck 5600 econominder a good DIY system for the softener?

Thank you all for your patience with us as newbies to all of this. We really appreciate your input!

 

[ditttohead]

I have retyped this many times, I just can come up with anything that isn't snarky, sarcastic, and I keep going back to the old saying, if you cant say anything nice...

Ask to see the PFOS and PFAS reduction certifications. This is a very bold claim since PFOS and PFAS are fairly difficult to reduce from water as is fluoride and most companies are not willing to spend the tens of thousands of dollars that it costs to certify these types of claims. Most carbons do not reduce fluoride effectively except for bone char. I would avoid companies that cant back these types of claims without real certifications or documentation.

 

[UnlimitydAl]

I have retyped this many times, I just can come up with anything that isn't snarky, sarcastic, and I keep going back to the old saying, if you cant say anything nice...

Ask to see the PFOS and PFAS reduction certifications. This is a very bold claim since PFOS and PFAS are fairly difficult to reduce from water as is fluoride and most companies are not willing to spend the tens of thousands of dollars that it costs to certify these types of claims. Most carbons do not reduce fluoride effectively except for bone char. I would avoid companies that cant back these types of claims without real certifications or documentation.

When I asked about certifications, this is what I got back. I'm going to ask specifically about the fluoride one, though.

All components, materials and filtration media used in our Whole House Water Filtration Systems comply with NSF/ANSI Standard 61: Drinking Water System Components – Health Effects. Additionally, the Granulated Activated Carbon (GAC) filtration media meets NSF/ANSI Standard 42. The pressure tanks feature a one piece, seamless high density polyethylene liner and an encapsulated, leak free engineered polymer inlet which comply with NSF/ANSI Standard 44. The Control Valves are also fabricated using composites that comply with NSF/ANSI Standard 44.



All components, materials and filtration media used in our 14-Stage Water Purification System comply with NSF/ANSI Standard 61: Drinking Water System Components – Health Effects. Additionally, all materials are safe and specifically chosen for compatibility with pure water. Plastics are BPA-free, food-grade and comply with NSF/ANSI Standard 61. Please know that the storage tank which houses the pure water contains a completely inert butyl rubber bladder such that the pure water never actually comes into contact with the sidewalls.

All tubing is food grade, FDA compliant Linear Low Density Polyethylene (LLDPE) which complies with NSF/ANSI Standard 61. They are not PVC. Though similar to PEX (also known as XLPE), LLDPE is better suited for pure water systems. As for the filter housings, they are made from reinforced polypropylene.

The follow components are also meet NSF/ANSI Standards:

1. 5 micron Sediment Pre-filter complies with NSF/ANSI Standard 42.
2. Carbon Pre-filter complies with NSF/ANSI Standards 42 and 53.
3. Reverse Osmosis Membrane complies with NSF/ANSI Standard 58 for the reduction of Arsenic, Barium, Cadmium, Chromium (Hexavalent), Chromium (Trivalent), Copper, Cysts, Turbidity, Fluoride, Lead, Radium 226/228, Selenium, and TDS.