8 ms·

PFAS is a pretty serious problem with US (and global) water supplies. There was a great documentary a couple years ago that covered it [0]. Even though they 's

PFAS is a pretty serious problem with US (and global) water supplies. There was a great documentary a couple years ago that covered it [0]. Even though they 'stopped' using these chemicals in manufacturing 10-15 years ago, there's still an incredible level of contamination - 26,000 sites listed by EPA [1]. But that's sort of irrelevant, because these compounds don't break up over human time scales. Eventually every place in the world will be contaminated, and with how harmful they are it's not clear if the old adage "the solution to pollution is dilution" will hold up. It's hard not to be alarmist about this, PFAS contamination is genuinely terrifying. [0] https://www.imdb.com/title/tt7689910/ https://www.imdb.com/title/tt7689910/ [1] https://en.wikipedia.org/wiki/Per-_and_polyfluoroalkyl_substances#United_States https://en.wikipedia.org/wiki/Per-_and_polyfluoroalkyl_subst...

forgotmypw17 6y ago
Is there a way to break them down? Let's say I have X liters of contaminated water I want to drink, how can I clean it, preferably without expensive or difficult to obtain equipment?
- voisin 6y ago
  Distillation?
  - dennis_jeeves 6y ago
    Yep, that is the right answer. Some volatile compounds may get through though.
- hammock 6y ago
  RO removes most of it. Cannot really be broken down easily, that's part of the problem.
- mrfusion 6y ago
  I think Brita and such can filter it out. Seemed like it last time I researched?
  - Scoundreller 6y ago
    Not sure if studies have been done on Brita itself, but yes, granulated/powdered activated charcoal is very effective at adsorbing it.
  - leetcrew 6y ago
    there are a lot of frustrating tradeoffs with these kinds of filter pitchers. they can remove a lot of nasty solutes, but they can also introduce bacteria. here's a study that found that brita-filtered water contained more bacteria than the tap water only a week into the filter's service life: https://pubmed.ncbi.nlm.nih.gov/8740859/ https://pubmed.ncbi.nlm.nih.gov/8740859/ I used to be a religious brita user, but now I just stick to tap. hard to assess the relative risk, but it's cheaper than buying filters.
    - nerdponx 6y ago
      Does this change if the pitcher is stored in the refrigerator versus on a countertop?
      - leetcrew 6y ago
        I didn't read past the abstract, but yes, they found that the bacteria count was also higher when stored in the fridge. presumably by less than the room temperature pitcher.
    - hammock 6y ago
      Undersink RO is not that difficult these days, and might be a good solution for you. I use Zerowater and I can tell when it gets a slight smell (bacteria I assume) , I just change the filter at that point even if it hasn't been ~3 months.
    - indecisive_user 6y ago
      Eh, drinking water with bacteria is plenty natural. Water with synthetic PFAS or lead, not so much. Unless the bacteria is actively causing harm or a variety known to be harmful to humans I'd still rather take my chances with the filters.
- yabones 6y ago
  It's not extremely clear, but it seems like the most effective way to remove PFAS from water is to essentially electrolyze it. > The electrochemical oxidation system used boron-doped diamond electrodes, in a process breaking down the contaminants’ formidable molecular bonds and cleaning the water while systematically destroying the hazardous compounds It's possible filtration may remove some of it, but this appears to be the only way to completely break it down at commercial scale. [1] https://en.wikipedia.org/wiki/Per-_and_polyfluoroalkyl_substances#Remediation_solutions https://en.wikipedia.org/wiki/Per-_and_polyfluoroalkyl_subst...
- Scoundreller 6y ago
  Breaking them down doesn't work that great. It might even oxidize precursors into the bad stuff Here's what works: > The following processes were found to be effective for the removal of PFOS: GAC (up to > 99 percent removal), membrane separation - high pressure membranes such as nanofiltration and reverse osmosis (up to > 99 percent removal), anion exchange (up to > 99 percent removal), and powdered activated carbon (up to 99 percent removal). https://tdb.epa.gov/tdb/contaminant?id=10940 https://tdb.epa.gov/tdb/contaminant?id=10940 Distillation is also said to work since these nasties have very high boilings points. Just don't run out of water in your distiller and let the temps get really high.
  - sizzle 6y ago
    Also add back in electrolytes
- sizzle 6y ago
  Will water distillation work to remove contaminants and impurities?
hammock 6y ago
>Even though they 'stopped' using these chemicals in manufacturing 10-15 years ago Citation needed. PFCs are EVERYWHERE, in TODAY's products. Everything from water-resistant workout pants, to your Chipotle burrito bowl container, to teflon-coated pasta extruders used in food manufacturing (which you cannot examine the way you can a non-stick pan to see whether it's degraded or not) to Glide dental floss that you put in your mouth daily. You won't find PFCs on the label of any of these examples, either. But they're there.
- mrfusion 6y ago
  What’s the safe alternative for glide floss?
  - hammock 6y ago
    Not really informed enough to answer this with confidence. A water pick?
    - Forbo 6y ago
      I've really enjoyed my water flosser, my only complaint has been how loud it is. Also, if you use a strong mouthwash in the reservoir there is the possibility it will etch and eat into the reservoir tank. I typically try to flush mine out with fresh water after each use.
  - jeffbee 6y ago
    Dr. Tung's Smart Floss. It's a polyester floss coated with beeswax, no teflon or PFA.
    - hammock 6y ago
      Why have you been downvoted?
      - jeffbee 6y ago
        A moderator will probably berate me for this meta-commentary, but there is a robot that comes along and down-votes all of my new comments regularly. I don't know if it is just me or every recent comment.
blablabla123 6y ago
That documentary sounds interesting, I need to watch that. Apart from that, it's quite obvious that most US tap water is not drinkable since it has this foamy, soft texture with a lot of chlorine. I wonder if there is any connection to that or if that is just a correlation.
cptskippy 6y ago
I'm going to weight in because my partner is an environmental engineer who performs remediation of PFAS contaminated sites for the EPA and other Federal entities. > Even though they 'stopped' using these chemicals in manufacturing 10-15 years ago, there's still an incredible level of contamination They haven't stopped using them, the chemicals are still used in stain and water resistant carpeting and textiles. They're used in cosmetics and sunscreens among other things. One of the biggest sources of contamination is fire retardant foams used in fire suppression. If you look at some of the sites in that report listed as having contaminated water, many are located near military bases, like Oceanside CA. These bases are the largest sources of ground water contamination of all sorts but specifically PFAS because they routinely practice fire suppression exercises. > 26,000 sites listed by EPA [1]. But that's sort of irrelevant, because these compounds don't break up over human time scales. PFAS is an emerging contaminant and isn't strictly regulated yet. Keeping track of these sites however is not irrelevant, it's extremely important that we know of and track these sites because they can and are being remediated. The current method of remediation involves setting up hundreds or thousands of ground water monitoring wells around a contamination site to track the plumes and then using pumps to remove the ground water and filter it through activated carbon filters. The filters are treated as hazardous waste and incinerated. > It's hard not to be alarmist about this, PFAS contamination is genuinely terrifying. I wouldn't say you're being alarmist at all, if anything the current response to PFAS is insufficient and we should be treating it as a public health crisis at least on par with Lead.
- hammock 6y ago
  >If you look at some of the sites in that report listed as having contaminated water, many are located near military bases, like Oceanside CA. These bases are the largest sources of ground water contamination of all sorts but specifically PFAS because they routinely practice fire suppression exercises. I read a report recently that suggested the DoD was scrambling to incinerate its firefighting foam supplies, to avoid a PR disaster. However, the safety of incineration as disposal method has been called into serious question, namely that it doesn't sufficiently break it down and instead distributes it more widely through the environment. Any insight from you or your partner?

forgotmypw17 6y ago

Is there a way to break them down? Let's say I have X liters of contaminated water I want to drink, how can I clean it, preferably without expensive or difficult to obtain equipment?

voisin 6y ago
Distillation?
- dennis_jeeves 6y ago
  Yep, that is the right answer. Some volatile compounds may get through though.
hammock 6y ago
RO removes most of it. Cannot really be broken down easily, that's part of the problem.
mrfusion 6y ago
I think Brita and such can filter it out. Seemed like it last time I researched?
- Scoundreller 6y ago
  Not sure if studies have been done on Brita itself, but yes, granulated/powdered activated charcoal is very effective at adsorbing it.
- leetcrew 6y ago
  there are a lot of frustrating tradeoffs with these kinds of filter pitchers. they can remove a lot of nasty solutes, but they can also introduce bacteria. here's a study that found that brita-filtered water contained more bacteria than the tap water only a week into the filter's service life: https://pubmed.ncbi.nlm.nih.gov/8740859/ https://pubmed.ncbi.nlm.nih.gov/8740859/ I used to be a religious brita user, but now I just stick to tap. hard to assess the relative risk, but it's cheaper than buying filters.
  - nerdponx 6y ago
    Does this change if the pitcher is stored in the refrigerator versus on a countertop?
    - leetcrew 6y ago
      I didn't read past the abstract, but yes, they found that the bacteria count was also higher when stored in the fridge. presumably by less than the room temperature pitcher.
  - hammock 6y ago
    Undersink RO is not that difficult these days, and might be a good solution for you. I use Zerowater and I can tell when it gets a slight smell (bacteria I assume) , I just change the filter at that point even if it hasn't been ~3 months.
  - indecisive_user 6y ago
    Eh, drinking water with bacteria is plenty natural. Water with synthetic PFAS or lead, not so much. Unless the bacteria is actively causing harm or a variety known to be harmful to humans I'd still rather take my chances with the filters.
yabones 6y ago
It's not extremely clear, but it seems like the most effective way to remove PFAS from water is to essentially electrolyze it. > The electrochemical oxidation system used boron-doped diamond electrodes, in a process breaking down the contaminants’ formidable molecular bonds and cleaning the water while systematically destroying the hazardous compounds It's possible filtration may remove some of it, but this appears to be the only way to completely break it down at commercial scale. [1] https://en.wikipedia.org/wiki/Per-_and_polyfluoroalkyl_substances#Remediation_solutions https://en.wikipedia.org/wiki/Per-_and_polyfluoroalkyl_subst...
Scoundreller 6y ago
Breaking them down doesn't work that great. It might even oxidize precursors into the bad stuff Here's what works: > The following processes were found to be effective for the removal of PFOS: GAC (up to > 99 percent removal), membrane separation - high pressure membranes such as nanofiltration and reverse osmosis (up to > 99 percent removal), anion exchange (up to > 99 percent removal), and powdered activated carbon (up to 99 percent removal). https://tdb.epa.gov/tdb/contaminant?id=10940 https://tdb.epa.gov/tdb/contaminant?id=10940 Distillation is also said to work since these nasties have very high boilings points. Just don't run out of water in your distiller and let the temps get really high.
- sizzle 6y ago
  Also add back in electrolytes
sizzle 6y ago
Will water distillation work to remove contaminants and impurities?

hammock 6y ago

>Even though they 'stopped' using these chemicals in manufacturing 10-15 years ago Citation needed. PFCs are EVERYWHERE, in TODAY's products. Everything from water-resistant workout pants, to your Chipotle burrito bowl container, to teflon-coated pasta extruders used in food manufacturing (which you cannot examine the way you can a non-stick pan to see whether it's degraded or not) to Glide dental floss that you put in your mouth daily. You won't find PFCs on the label of any of these examples, either. But they're there.

mrfusion 6y ago
What’s the safe alternative for glide floss?
- hammock 6y ago
  Not really informed enough to answer this with confidence. A water pick?
  - Forbo 6y ago
    I've really enjoyed my water flosser, my only complaint has been how loud it is. Also, if you use a strong mouthwash in the reservoir there is the possibility it will etch and eat into the reservoir tank. I typically try to flush mine out with fresh water after each use.
- jeffbee 6y ago
  Dr. Tung's Smart Floss. It's a polyester floss coated with beeswax, no teflon or PFA.
  - hammock 6y ago
    Why have you been downvoted?
    - jeffbee 6y ago
      A moderator will probably berate me for this meta-commentary, but there is a robot that comes along and down-votes all of my new comments regularly. I don't know if it is just me or every recent comment.

blablabla123 6y ago

That documentary sounds interesting, I need to watch that. Apart from that, it's quite obvious that most US tap water is not drinkable since it has this foamy, soft texture with a lot of chlorine. I wonder if there is any connection to that or if that is just a correlation.

cptskippy 6y ago

I'm going to weight in because my partner is an environmental engineer who performs remediation of PFAS contaminated sites for the EPA and other Federal entities. > Even though they 'stopped' using these chemicals in manufacturing 10-15 years ago, there's still an incredible level of contamination They haven't stopped using them, the chemicals are still used in stain and water resistant carpeting and textiles. They're used in cosmetics and sunscreens among other things. One of the biggest sources of contamination is fire retardant foams used in fire suppression. If you look at some of the sites in that report listed as having contaminated water, many are located near military bases, like Oceanside CA. These bases are the largest sources of ground water contamination of all sorts but specifically PFAS because they routinely practice fire suppression exercises. > 26,000 sites listed by EPA [1]. But that's sort of irrelevant, because these compounds don't break up over human time scales. PFAS is an emerging contaminant and isn't strictly regulated yet. Keeping track of these sites however is not irrelevant, it's extremely important that we know of and track these sites because they can and are being remediated. The current method of remediation involves setting up hundreds or thousands of ground water monitoring wells around a contamination site to track the plumes and then using pumps to remove the ground water and filter it through activated carbon filters. The filters are treated as hazardous waste and incinerated. > It's hard not to be alarmist about this, PFAS contamination is genuinely terrifying. I wouldn't say you're being alarmist at all, if anything the current response to PFAS is insufficient and we should be treating it as a public health crisis at least on par with Lead.

hammock 6y ago
>If you look at some of the sites in that report listed as having contaminated water, many are located near military bases, like Oceanside CA. These bases are the largest sources of ground water contamination of all sorts but specifically PFAS because they routinely practice fire suppression exercises. I read a report recently that suggested the DoD was scrambling to incinerate its firefighting foam supplies, to avoid a PR disaster. However, the safety of incineration as disposal method has been called into serious question, namely that it doesn't sufficiently break it down and instead distributes it more widely through the environment. Any insight from you or your partner?