Pure Water Occasional, February, 2024
 
 
In this late winter Occasional you'll read about water treatment for rainwater, truth and untruth in advertising, adsorption vs. absorption, PFAS in rainwater, leading water problems and how to deal with them, atmospheric rivers, drugs in river water, Greenland's new wetlands, nutrient pollution, decaffeinating coffee with water, and, as always, much, much more.

Thank you for reading, and sincere thanks from Pure Water Products for your continuing support.  
 
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Please visit the Pure Water Gazette, where you will find hundreds of articles about water and water treatment, and the Pure Water Products main website, where there is much information about water treatment and specific information about the products we offer. On both of these information-rich sites, pop-up ads and other distractions are not allowed.
 
 

 

Water Treatment for Rainwater

As water becomes scarce, rainwater collection systems are becoming increasingly popular.

After rainwater is collected and stored for later use, water treatment is essential. This usually takes the form of filtering out large particles then treating for microbiological safety. If the water is contaminated with chemicals from its collection process (for example, roofing materials if the water is collected from a roof), then a good carbon filter should be added to the treatment. Rainwater is no longer to be considered chemical free, so carbon filtration should probably be an essential part of any rainwater system used to furnish drinking water.  (See article below on PFAS contamination of rainwater.)

Filtering for sediment is usually done with a simple cartridge-style sediment filter or with a series of such filters. Filtration of the final product should be down to at least 5 microns.  

It is critical that some form of disinfection be used. This can be:
Chlorination, the old standby, followed by carbon filtration to remove the chlorine.

Ultraviolet (UV), which is probably the most popular single rainwater treatment. The water must be very clean when it passes the UV lamp to assure complete disinfection. UV has the advantage of adding no chemicals to the water. It should be the last stage in the treatment process.

Ozonation is an excellent disinfectant, but is a bit more challenging from the technical viewpoint.

Ultrafiltration (UF) is gaining popularity in rainwater treatment. UF filters down to about 0.02 microns—enough to remove cysts, bacteria and viruses. Again, water must be pre-filtered before the UF membrane to protect it from premature clogging.

Rainwater, with only the minimal treatment described above, can provide extremely good water. Its mineral content (TDS: Total Dissolved Solids) is very similar to that of reverse osmosis water.
 

(Un)Truth in Advertising

 
 
As far as I know, there's no law against making outrageously stupid statements, although there probably should be if only to protect advertisers from making fools of themselves.

There are certain water treatment myths and exaggerations that have been repeated so many times that people who say them actually believe them. Like, "Reverse osmosis does not remove chlorine," or "Carbon filters don't remove chloramines."

Here's a clip from a website touting a drinking water filter that contains the popular and very useful filter medium KDF55. The ad is in bold type and my comments are in italics.

Independent laboratory tests confirm that KDF®55 is one of the best media for improving drinking and bathing water naturally and economically. That is why we incorporate it into our technology.
  • Compared to carbon-only units, KDF®55 lasts far longer, doesn't’t permit bacterial growth, and removes a much wider range of inorganic matter (e.g. heavy metals).
    While this is all true to a degree, you could also say: 
 
  • Compared with carbon filters, KDF55 does not improve taste and odor appreciably, does not treat most organic chemicals, does not work well at all if not accompanied by carbon, does not treat VOCs, does not remove chloramines, etc. for pages and pages.
 
  • Compared to reverse osmosis, KDF®55 is less expensive, wastes no water, does not require membrane replacement, works at most water temperatures and pressures, and removes chlorine.
\
  • Compared with reverse osmosis, KDF does not remove fluoride, does not remove nitrates, does not reduce dissolved solids, does not remove sodium, does not remove chlorides, cannot desalinate sea water, does not remove hardness, etc., etc. for about forty pages.
 
  • Compared to ultraviolet lights, KDF®55 works in cloudy water, doesn’t require bulb replacement or electricity, and removes inorganics.
 
  • Compared with ultraviolet light, KDF does not keep water safe from e. Coli, does not kill viruses, does not kill cryptosporidium or Guardia, etc. etc. for many pages.
 
  • Compared to ozone, KDF®55 provides a residual effect to keep bacteria from growing in water, does not require electricity, and costs far less to buy and maintain.
 
  • Compared with ozone, KDF does not oxidize significant amounts of iron or hydrogen sulfide, does not make non-potable water safe for drinking, does not act as a disinfectant, etc.
 
 
 
 
KDF 55 is very useful product. We use it a lot in carbon/KDF filters, and it's the main ingredient in most shower filters sold today. But to try to compare a KDF filter to a reverse osmosis unit is like comparing a fish to a bicycle. Compared to a fish, a bicycle cannot swim into deep river channels, has to have air in its tires, and is difficult to peddle uphill. That's fine, but does it really prove that fish are superior to bicycles? It isn't any sillier than the attempt to compare KDF, a granular filter medium made of copper and zinc, to ultraviolet light. Doesn't require bulb replacement?  
 
 
 


Adsorption of Water Contaminants: How Filter Carbon Works

According to the Wikipedia,  “Adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface. This process creates a film of the adsorbate on the surface of the adsorbent. This process differs from absorption, in which a fluid (the absorbate) permeates or is dissolved by a liquid or solid (the absorbent). Note that adsorption is a surface-based process while absorption involves the whole volume of the material.”
Explained more graphically:
 
This man has adsorbed a pie.
 
 
This man is absorbing a pie.
In water treatment, activated carbon is the main adsorbing agent. This is true because filter carbon has an amazing amount of surface area and a strong ability to attract and hold organic chemicals.
Most of the surface area of a particle of carbon is internal.
Enlargement of granular carbon shows countless pores that adsorb contaminants. The surface area of the pores is exceptional. A single pound of activated carbon has more surface area in its pores than 100 football fields.
Carbon’s amazing ability to adsorb organic chemicals varies according to the chemical in question and conditions of the water. In general, chemicals of high molecular weight and low solubility are most easily adsorbed. The lower the concentration of the chemical, the higher the adsorption rate by carbon. Also, the fewer the interfering organic compounds present in the water the better. The pH of the water is also significant, with acidic compounds being most readily adsorbed at low pH. And, as with most other aspects of water filtration, rate of flow of the water being treated is extremely important with carbon adsorption. The more residence time the better.
In regard to specific chemicals, one source lists dozens of common chemicals and ranks them according to the likelihood that they will be removed by carbon adsorption. Here are a few of the more common items from the list:
Very High Probability of Adsorption: Atrazine, Malathion, 1, 3-dichlorobenzene,  DDT, Lindane.
High Probability of Adsorption: Toluene, styrene, benzene, carbon tetrachloride, vinyl acetate,  phenol.
Moderate Probability of Adsorption: Chloroform, vinyl chloride, acetic acid.
Unlikely to be adsorbed by carbon:  Isopropyl alcohol, dimethylformaldehyde, propylene.
It should be remembered that although carbon has great chemical reduction capacity because of its ability to attract and hold chemicals on its surface, it acts in other ways as well. Chlorine, for example, is reduced mainly by catalytic reaction with the carbon, not by the “grab and hold” process of adsorption.

 Rainwater Everywhere Contains Unsafe Levels Of PFAS

By Peter Chawaga

 
Drinking water and wastewater managers throughout the U.S. are keenly aware of just how pervasive per- and polyfluoroalkyl substances (PFAS) can be in the environment. But now, new research has found that all rainwater around the world contains these contaminants to unsafe degrees.
“Atmospheric levels of toxic ‘forever chemicals’ are so high that rainwater everywhere contains amounts that are unsafe for long-term human consumption according to safety guidelines,” Vice reported. “‘Even in these remote and sparsely populated regions, such as Antarctica and the Tibetan plateau, the most stringent PFAS guidelines are exceeded,’ according to a study.”
But this latest study underscored the fact that PFAS are nearly impossible to avoid, no matter what actions water and wastewater systems take.
“This new study, which looks at four specific chemicals in the class, suggests that levels of one PFAS in rainwater around the globe often ‘greatly exceed’ US drinking water advisory levels,” according to the BBC. “The study’s findings lead the authors to conclude that a planetary boundary has been crossed — that there simply is no safe space on Earth to avoid these substances.”
As researchers learn more about PFAS and the potential harm that can come from exposure to them, regulations are becoming stricter. And while the production of products containing PFAS has been largely phased out, these so-called forever chemicals remain in the environment for a notoriously long time.
With the global environment now found to be totally inundated with PFAS, much of the burden for keeping these compounds away from consumers continues to fall on drinking water treatment operations.
“Removing the chemicals in the study from drinking water at treatment plants is possible, if expensive,” per BBC. “But getting below the US advisory levels is extremely challenging, according to the authors.”

 

 
 

 

 
 
Tons of Information
 
We've been collecting information about water and water treatment since the 1980s. We invite you to make use of it.
 
The Pure Water Gazette website has well over a thousand articles on water and related issues. Read to your heart's content in a popup-free environment.
 
Pure Water Products main website has lots of fairly well organized information about most aspects of water treatment. Please visit and read at leisure without insulting BUY NOW! intrusions.
 
We've lost track of how many back issues of the Pure Water Occasional we have archived, but you can find links to many of them here. 
 
 
 

 

Leading Water Issues, Old and New

by Emily McBroom and Gene Franks

 
 
The statement,”my parents drank this water for 50 years, and it never hurt them” is no longer a valid excuse for consumers to not be concerned with their water quality.—Greg Reyneke.

In an article in H2O Quality magazine, water treatment expert Greg Reyneke (see note below) commented on recent information that has surfaced about some old water treatment issues. Below are Greg’s comments, followed by some observations of our own which suggest practical approaches to dealing with the contaminants. Greg’s comments are italicized.
 
 
Arsenic

A 2010 assessment by the Environmental Integrity Project suggests that the risk of getting cancer from drinking water containing 10 ppb of arsenic is closer to 1 in 136, almost 15 times higher than current EPA assumptions (1 in 2000). Many scientists say the increased risk of cancer in humans who drink water, inhale dust, or ingest soil contaminated with high levels of inorganic arsenic puts the chemical’s danger level in the same category as that of smoking cigarettes.


The acceptable maximum level for arsenic in drinking water, as recommended by the EPA, is just 1/5 what it was a few years ago. Removing arsenic from a small amount of drinking water is fairly easy, while point-of-entry removal is difficult and expensive. Since arsenic is mainly an ingestion issue, we recommend removing it from drinking water and practicing common sense avoidance for other water in the home. In other words, drink water from your kitchen reverse osmosis (RO) unit, not from the bathroom sink.  The best drinking water treatment for arsenic is reverse osmosis. Undersink filters with iron oxide media are also effective. Whole house arsenic treatment is possible but expensive and requires considerable upkeep.
 
 
Bacteria and Waterborne Pathogens

 
Bacteria exist in ALL water at some level, even safe, chlorinated city water. Some bacteria are relatively “safe,” but there are other potential problems like brain-eating amoeba that have been found in certain waters. The expense and difficulty of consistent testing often means that contamination may go undiscovered for extended periods of time.

 
By far the best residential treatment for bacterial contamination is ultraviolet. UV was at one time mainly used almost exclusively with well water, but because of growing concerns over the effectiveness of city water disinfection, and because of frequent “boil water” alerts, whole house UV units are now becoming common items in homes with municipal water. UV can also be used for point of use applications, but it costs so little extra to do the whole house, point of entry systems are most common. UV is a reliable technology that adds nothing objectionable to the treated water. It is easy and relatively inexpensive to maintain.
 
 
Chlorine and Chloramine

 
While chlorination of water is probably one of the most significant contributors to lowering the risk of waterborne illness in the USA, there are significant negative effects, such as taste and odors, corrosion, and even a correlation to the development of some cancers.

 
Removing chlorine or chloramine from water for the whole home or for drinking water only is best accomplished with carbon filtration. There are innumerable products to choose from, including large tank-style filters, carbon block cartridges, and even small filters built into refrigerators. Whole house filters can remove chlorine or chloramine,  but tighter drinking water filters are more effective at removing other chemical contaminants that might be present in the water. An excellent residential treatment plan is a whole house carbon filter to provide chlorine/chloramine-free water for bathing and general household purposes, and a drinking water unit, either a tight carbon block filter or reverse osmosis unit, for drinking water only. In general, chloramine is much harder to remove than chlorine. Chloramine removal filters are larger and use better quality carbon (catalytic carbon) to do the job.
 
 
Hard Water Scale and Soap Interactions 

 
While many people might consider hard water to be a simple aesthetic issue, it really is bigger than that. Hard water is a significant drain on a family’s monthly budget and has a decidedly negative impact on the planet due to increased heating and cleaning expenses, along with premature appliance failure. Consumers are clamoring for low-salt and no-salt solutions to their hard water problems that “waste” a minimum amount of water.
 
While there is no substitute for the conventional salt-based ion exchange water softener, salt-free alternatives, especially TAC (Template Assisted Crystallization) units, are growing in popularity fast. While TAC units don’t do some of the things softeners do, they have the advantage of requiring no salt, electricity, or connection to a drain. They don’t use water for regeneration or add salt to wastewater. 
 
 
Lead

 
While Flint, Michigan, captured the imagination of the nation, lead can also be found at some level in other areas. In 2017, 779 Texas schools (about 71%) were reported to have lead in their drinking water, according to an analysis of testing data by Environment Texas Research and Policy Center. Lead is a potent neurotoxin, affecting the way children learn, grow, and behave, which can cause problems that will persist into adulthood.
 
Lead is a tricky issue, because lead in drinking water often comes from the pipes inside the home itself, making a “whole house” filter for lead pointless. Nevertheless, growing evidence shows that infrastructure issues, old lead city water pipes in particular, are adding lead to water coming into homes. Lead can be removed by ion exchange and by special carbon block filters with added resins, but reverse osmosis is the best treatment for drinking water. As with many contaminants, lead is mainly an ingestion issue, so having a good reverse osmosis unit in the kitchen is the most practical treatment.
 
Manganese

 
The serious health risks of consuming water containing manganese have been overlooked for far too long. Long-term consumption of even low levels are now related to complications involving alterations in neurotransmitter and enzyme levels in the brain that can cause nerve damage, brain changes, hormone alteration, and possibly even the proliferation of certain cancers.
 
Manganese is normally a well water issue, but we increasingly hear reports of manganese in water from central suppliers, especially small water systems. Manganese, regardless of the source, is a significant aesthetic issue, causing odors and dark stains, and it is now being regarded as a health issue as well. Whole house treatments can be complicated, but they can also be as simple as a conventional water softener or a backwashing filter. For drinking water, reverse osmosis assures manganese-free water.
 
Perfluorinated Compounds (PFC, PFOS, PFOA)
 
Perfluoroalkyls are not natural, and PFOA and PFOS are the two types that have typically been found in the largest amounts. These substances are unique because they repel oil, grease, and water – meaning they have been used to help produce countless convenient modern products. Exposure levels of these chemicals can already be found in the blood of most Americans. Health risks from exposure to these chemicals include hormone disruption, fertility issues, and even certain cancers.
 
Although treatment for perfluorinated compounds in municipal systems can be complex, carbon filtration for whole house and reverse osmosis for drinking water have been found to provide significant reduction for homes.
 
Nitrates
 
One other issue we would like to add to the list of regulated contaminants that should be taken more seriously is nitrates.  There is growing evidence that nitrate contamination is becoming much more common, not only in well water but also in city water supplies. The long-standing EPA allowable amount of 10 parts per million may be way too lenient. Although nitrates can be removed with ion exchange, the best and easiest way to provide nitrate-free drinking water is with an undersink RO unit in the home.
 
Conclusion

Of the issues discussed, whole house treatments are practical for bacteria and hardness. For city water with chlorine, chloramine, and general chemical issues, including PFAS, an appropriately designed and sized whole house carbon filter is recommended. For drinking water issues like lead, nitrates, and arsenic, an undersink reverse osmosis unit is the treatment of choice. A good undersink RO unit covers virtually all drinking water issues. It includes carbon block filters for chemical reduction and a very tight membrane that strains out lead, arsenic, fluoride, nitrates, sodium, and other undesirables.
 
Reference: Greg, Reyneke, “It’s Up to You,” H2O Quality (a publication of the Texas Water Quality Association), Winter, 2019.  pp. 10-12.  See also www.gregknowswater.com .
 
 
 

 

Water News —February, 2024

 
Underground Ocean

Scientists have uncovered an entire ocean hidden beneath 15 miles of ice on Saturn’s moon Mimas. Details. 

U.S. Groundwater is drying up at a "rapid and accelerating rate"

New research on groundwater loss has identified the most severely impacted states in the U.S., with the nation’s breadbasket facing significant threats.

“The collapse of groundwater reserves beneath California’s Central Valley stands out as particularly severe — even among all the global losses,” per a follow up report from The Hill.

 “Currently, California accounts for 21 percent of total groundwater usage in the U.S., and draws about 67 percent of its fresh water from its groundwater reserves. That reliance is taking a toll: Of California’s 183 groundwater basins evaluated by the Nature team, three-quarters are in decline — and for many, that decline is occurring very quickly.”

That report identified Texas, Idaho, Arizona, Utah, and Mississippi as the other severely impacted states, with Oklahoma, New Mexico, and Kansas also mentioned.  Water Online.  


Medicinal drugs polluting the St. Lawrence River are threatening aquatic wildlife.

The river flows from Canada's Lake Ontario all the way to the Gulf of St. Lawrence, connecting the U.S. Great Lakes to the North Atlantic. The new study, published in ScienceDirect from researchers at the University of Montreal, found concerning levels of pharmaceutical pollution in its waters, mainly in its flows near urban areas.

Researchers studied a 400 mile stretch of the river and discovered four medicinal compounds in such high quantities that there is the potential to seriously affect marine life. The compounds found were caffeine, carbamazepine, diclofenac and ibuprofen.


Heavy Water Pollution from Meat Processing.

The U.S. EPA has been moving toward stricter standards for slaughterhouse effluent for months, recently detailing how it would utilize pollution control technologies to drive reductions in nitrogen, phosphorus, and other pollutants from the industry’s wastewater. These pollutants can foster the growth of toxic algae and otherwise harm the environment and source water quality. Slaughterhouses are fighting stronger standards.
 

“The proposed guidelines aim to cut the pollution by 100 million pounds annually, mainly from meat processors that slaughter at least 50 million pounds of meat or 100 million pounds of poultry annually,” according to Bloomberg Law. “They also establish pre-treatment standards for oil and grease and other pollutants. The rules would apply to about 850 of the 5,000 meat and poultry producers nationwide.”   WaterOnline 
 

Atmospheric Rivers

Atmospheric River is a term we're hearing more frequently. 

"An atmospheric river is a narrow corridor or filament of concentrated water vapor transported in the atmosphere. It’s like a river in the sky that can be 1,000 miles long. On average, atmospheric rivers have about twice the regular flow of the Amazon River." Here's a good article from Scientific American that includes information about how global warming is affecting Atmospheric Rivers.   As a result of recent Atmospheric River rains, California's Tulare Lake is re-emerging after 138 years.   Details. 

Outrageous Amounts of Water Are Required to Provide Animal Feed

Along with vast amounts of land, growing crops for animal feed requires enormous quantities of water. In the U.S. alone, more than 60 percent of freshwater was used to grow crops in 2012, and around 2.5 trillion gallons per year of water was used for animal feed in the same year. Corn, soybeans, and the other grains used in animal feed require about 43 times more water than grass or roughage, which animals could access if they were allowed to graze. Wiki Observatory.
 
Phosphorus Pollution Takes A Long Time to Go Away


Phosphorus lingering in waterway sediments for years may help to explain how nutrient pollution continues in the Gulf of Mexico, even after Midwest states met their discharge-reduction goals.It is believed that current policies to reduce nutrient pollution are working, but seeing results will take time.  Stormwater Management.


Can Wetlands Be Bad For the Environment?  Depends on Where They Are

Research shows there has been a near-quadrupling across Greenland of methane-producing wetlands. Significant areas of Greenland’s melted ice sheet are now producing vegetation, risking increased greenhouse gas emissions, rising sea levels and instability of the landscape.

A study has documented the change since the 1980s and shows that large areas of ice have been replaced with barren rock, wetlands and shrub growth, creating a change in environment.  The Guardian

Plastics makers have been lying for years about recycling of plastics

Plastic producers have known for more than 30 years that recycling is not an economically or technically feasible plastic waste management solution. That has not stopped them from promoting it, according to a new report.

“The companies lied,” said Richard Wiles, president of fossil-fuel accountability advocacy group the Center for Climate Integrity (CCI), which published the report. “It’s time to hold them accountable for the damage they’ve caused.”

Plastic, which is made from oil and gas, is notoriously difficult to recycle. Doing so requires meticulous sorting, since most of the thousands of chemically distinct varieties of plastic cannot be recycled together. That renders an already pricey process even more expensive. Another challenge: the material degrades each time it is reused, meaning it can generally only be reused once or twice.  The Guardian
 


 

 

How Caffeine Is Stripped from Coffee by Use of the Chemical-Free Water Method


Caffeine is in the coffee bean for a reason.  It’s a natural alkaloid that serves the coffee plant as a pesticide.  It paralyzes bugs that invade the plant and also gives off a bitter flavor as a warning of its toxic nature.

Caffeine is water soluble, as are most of the other ingredients of the bean that give coffee its flavor.

The art of decaffeination,  therefore, consists of stripping the caffeine from the coffee bean while leaving behind the desirable ingredients that provide the coffee taste and aroma.

Several methods are used to remove caffeine from coffee.  Many involve chemicals, but others rely almost entirely on water.  The water methods are definitely the more desirable.  The so-called Swiss Method is considered the standard of excellence.  Here’s how the process is described:

The green, or unroasted coffee is fully submerged in filtered water that has been heated, in order to extract all the soluble material from the beans. The water solution is then filtered through carbon to separate the caffeine compounds from any of the aromatics that also came out during the extraction, and the coffee beans are then placed in an immersion tank with the caffeine-free solution, allowing them to reabsorb everything but the jitters.
World standards differ on the definition of “decaffeinated coffee,”  some allowing 97% caffeine reduction, but the highest  standards require elimination of  as much as 99.9% of the alkaloid content of coffee in order to display the decaffeinated label.

Reference:
 
 
 
 
 
 
 
 
Places to visit for additional information:

 
 
 
 
 
 
 
Thanks for reading. 
Pure Water Products, LLC, 523A N. Elm St., Denton, TX, 76201.  www.purewaterproducts.com. Call us at 888 382 3814, or email pwp@purewaterproducts.com.
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