Rainwater almost everywhere on Earth has unsafe levels of 'forever chemicals', according to new research.
https://www.euronews.com/green/2022/08/04/rainwater-everywhere-on-earth-unsafe-to-drink-due-to-forever-chemicals-study-finds
Thanks for posting that.
For those dependent on rainwater for drinking water, are there any water filters that can filter out those chemicals?
Yes they both can be filtered effectively with proper reverse osmosis and activated carbon filtration. Distillation has also been shown to be effective. Tap based activated carbon filters or pitcher type filters tend to be the cheapest effective filtration method for most home users (YMMV).
https://hammer.purdue.edu/articles/thesis/Per-and_polyfluoroalkyl_substances_PFAS_removal_in_drinking_water_with_point-of-use_water_treatment_systems/14502444/1
QuoteThe results showed that PFAS were effectively removed in both RO and AC systems with average removal efficiencies greater than 90% in all tested POU systems.
https://pubmed.ncbi.nlm.nih.gov/32585466/
Quote In this study, the treatment efficiency for the removal of 15 PFASs was examined in a full-scale drinking water treatment plant (DWTP) in the City of Uppsala, Sweden, over a period of two years (2015-2017). Removal of the five frequently detected PFASs was influenced by the total operation time of granular activated carbon (GAC) filters, GAC type and surface loading rate. The average removal efficiency of PFASs ranged from 92 to 100% for "young" GAC filters and decreased to 7.0-100% for "old" GAC filters (up to 357 operation days, 29 300 bed volumes (BV) treated).
https://cfpub.epa.gov/si/si_public_record_report.cfm?Lab=CESER&dirEntryId=352130&submit=Search
Quote U.S. EPA conducted treatability studies on the PFAS removal effectiveness of commercially available Point-of-Use/Point-of-Entry (POE) Reverse Osmosis (RO) treatment units and Granular Activated Carbon (GAC).
This BTW is a good place to start looking at how to remove chemicals from water is here.
https://tdb.epa.gov/tdb/home
NFS is a national standard setting organization for many things one is water filters. If you check the container for the water filter you will typically see a NSF 42 certification on filters that remove only bad taste if you see an NSF 42 & NSF 53 certification that means that the product listed for NSF 53 (typically lead) does meet the claimed reduction level but that only that product listed was tested and certified.
Quote- If you want to know if a filter is NSF approved for the removal of PFOA and PFOS, search for the NSF P473 or NSF P474 certification marks.
https://waterfilterguru.com/nsf-ansi-standard-certifications-explained/
SOB, I'm a veg and can't figure out how to bookmark this to come back to read later. Hence me posting this...
Carry on.
I guess I should stop using unfiltered rainwater for my hydroponic vegetables. They seemed to grow better with the rainwater than with filtered tap water, so this sucks.
Also, there was a hullabaloo in my area because there was evidence that the feds discovered that wells in the area were contaminated with PFAS but didn't provide that information to anyone at the state or local level, so residents weren't warned until months after it was discovered. If you have a well, test regularly.
Quote from: Anianna on August 11, 2022, 10:48:38 PMI guess I should stop using unfiltered rainwater for my hydroponic vegetables. They seemed to grow better with the rainwater than with filtered tap water, so this sucks.
Also, there was a hullabaloo in my area because there was evidence that the feds discovered that wells in the area were contaminated with PFAS but didn't provide that information to anyone at the state or local level, so residents weren't warned until months after it was discovered. If you have a well, test regularly.
Opinion not fact here but for grey water uses like washing or watering plants low levels of PFAS in the water should not be an issue. Obviously the level PFAS as well as the soil (ph, salinity, organic matter) has an impact on that statement.
https://pubmed.ncbi.nlm.nih.gov/30502744/
https://www.sciencedirect.com/science/article/abs/pii/S0045653520317793
Some ground water has very high levels of PFAS.
https://federalnewsnetwork.com/defense-main/2022/08/defense-department-sites-are-rife-with-poisons-in-nearby-groundwater/
Even at these high levels the PFAS can be removed and/or filtered down to safe levels. The key (like any contaminant)is to ID the contaminant and its level.
I agree testing well water on a routine basis is useful. That and using a good activated carbon filter on potable water uses (drinking water, cooking) makes a lot of sense. As simple faucet mounted or pitcher type filter which meets both NSF 42 & 53 standards goes a long way to reducing any contaminants. I would note that many refrigerators have an AC water filter most of these are only NSF 42 standard (i.e taste) but if you use this source to put into a pitcher type filter for drinking water you get the benefit of both filtration cycles.
A youtube channel project farm did a test on pitcher type filters. Note this is not a great way to test removal of PFAS but it is a consistent test on removing solids.
https://www.youtube.com/watch?v=ja0ioX6GSz0
BTW when buying water filters do look for the NSF certification and read the fine print.
This is listing of NSF tested items and the things they filter per NSF certification.
https://info.nsf.org/Certified/DWTU/Listings.asp?ProductFunction=053%7CPFOA+Reduction&ProductFunction=053%7CPFOS+Reduction&ProductFunction=P473%7CPFOA+Reduction&ProductFunction=P473%7CPFOS+Reduction&ProductType=&submit2=Search
One of the really big problems with water and water contaminants is that finding data on the subject is tough. There are a lot of people selling a lot of filtration products they are very good at their SEO processes. My rule of thumb is that a site selling something is not a reliable source of data. It may or many not be correct but you should verify that data before using it.
Also bottled water may have PFAS in it.
https://www.consumerreports.org/bottled-water/bottled-water-brands-with-concerning-pfas-levels-a6560338667/
Quote from: Raptor on August 12, 2022, 10:56:41 AMQuote from: Anianna on August 11, 2022, 10:48:38 PMI guess I should stop using unfiltered rainwater for my hydroponic vegetables. They seemed to grow better with the rainwater than with filtered tap water, so this sucks.
Also, there was a hullabaloo in my area because there was evidence that the feds discovered that wells in the area were contaminated with PFAS but didn't provide that information to anyone at the state or local level, so residents weren't warned until months after it was discovered. If you have a well, test regularly.
Opinion not fact here but for grey water uses like washing or watering plants low levels of PFAS in the water should not be an issue. Obviously the level PFAS as well as the soil (ph, salinity, organic matter) has an impact on that statement.
https://pubmed.ncbi.nlm.nih.gov/30502744/
https://www.sciencedirect.com/science/article/abs/pii/S0045653520317793
Some ground water has very high levels of PFAS.
https://federalnewsnetwork.com/defense-main/2022/08/defense-department-sites-are-rife-with-poisons-in-nearby-groundwater/
Even at these high levels the PFAS can be removed and/or filtered down to safe levels. The key (like any contaminant)is to ID the contaminant and its level.
I agree testing well water on a routine basis is useful. That and using a good activated carbon filter on potable water uses (drinking water, cooking) makes a lot of sense. As simple faucet mounted or pitcher type filter which meets both NSF 42 & 53 standards goes a long way to reducing any contaminants. I would note that many refrigerators have an AC water filter most of these are only NSF 42 standard (i.e taste) but if you use this source to put into a pitcher type filter for drinking water you get the benefit of both filtration cycles.
A youtube channel project farm did a test on pitcher type filters. Note this is not a great way to test removal of PFAS but it is a consistent test on removing solids.
https://www.youtube.com/watch?v=ja0ioX6GSz0
BTW when buying water filters do look for the NSF certification and read the fine print.
This is listing of NSF tested items and the things they filter per NSF certification.
https://info.nsf.org/Certified/DWTU/Listings.asp?ProductFunction=053%7CPFOA+Reduction&ProductFunction=053%7CPFOS+Reduction&ProductFunction=P473%7CPFOA+Reduction&ProductFunction=P473%7CPFOS+Reduction&ProductType=&submit2=Search
One of the really big problems with water and water contaminants is that finding data on the subject is tough. There are a lot of people selling a lot of filtration products they are very good at their SEO processes. My rule of thumb is that a site selling something is not a reliable source of data. It may or many not be correct but you should verify that data before using it.
Also bottled water may have PFAS in it.
https://www.consumerreports.org/bottled-water/bottled-water-brands-with-concerning-pfas-levels-a6560338667/
I'll still use rainwater for my houseplants. I'm only concerned about using unfiltered rain water on the consumable vegetables. No soil in my hydro/aeroponics systems, so it's all about what's in the water.
Interesting about the bottled water. I know the rules vary by state, but bottled water is almost always tap water and that seems to indicate that they are sourcing from states with poor standards. I keep an eye on the reports for our municipal water and have the NSF certified filter system for our drinking water, but our municipal water consistently measures within acceptable limits. I did run a test on it myself when we first moved in, but I haven't since. I should probably do that again. I used to test annually when we had a well.
Some potentially good news on this front:
https://www.livescience.com/pfas-forever-chemicals-broken-down
QuoteScientists discovered a simple destruction technique that works on 10 types of these chemicals, known as per- and polyfluoroalkyl substances (PFAS). Researchers hope that the method will expose weaknesses in even more PFAS-class substances, leading to paths for removing these chemicals from drinking water easily and cheaply.