Pure Water Occasional. June, 2025
 

​​In this early summer Occasional you'll hear about absolute and nominal micron ratings for water filters, the best fluids to hydrate your body, the lifespan of water filter cartridges, how to cope with boil water alerts if you have a whole house water filter, the sad fate of glaciers, a crypto outbreak, the hazards of eating fish caught in PFAS-contaminated waters, a scary diesel spill in Baltimore, the salmonella threat posed by cucumbers grown in areas with contaminated water, elephants killed by polluted water, National Hydration Day, sky-high PFAS contamination in a Swedish town, the threat of arsenic in water to expectant mothers, whole house cartridge filters, aeration for well water, where to get a high-quality test for your home's water, and, as always, there is much, much more.

Thank you for reading, and sincere thanks from Pure Water Products for your continuing support.  
 
Thanks for reading!

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.
 
 
 

Pure Water Gazette Technical Wizard Pure Water Annie Answers All the Persistent Questions about Water Treatment.

 
 
Nominal vs. Absolute
 

If you’re puzzled by what filter makers mean when they call their filters “absolute” or “nominal,” technical wizard Pure Water Annie will clear the matter up for you. 
 

Water filtration devices are rated by the sizes of particles that will pass through them. The ratings are normally expressed in microns.
 

Micron ratings are applied to all types of filtration devices, including even granular filters. It is said, for example, that a sand filter is roughly a 10 micron filter, meaning that it filters out particles ten microns and larger in girth. Carbon block filters are also assigned micron sizes, but micron ratings are most meaningful in comparing sediment filters.
 

The micron is a standard measure of size that is used by filter makers. The diameter of a human hair is about 90 microns. Sediment filters are used to catch particles 1/300 of that.
 

Most sediment filters are given ratings by their manufacturers that describe their effectiveness at removing particles down to a specified size. The most common of these are ”nominal” and “absolute.”
 

Nominal, according to the Water Quality Association (WQA), means that the filter will filter out at least 85% of the particles of the size it is rated for. In other words, a filter that is rated as a 1 micron nominal can be expected to pick out 85% of the particles that are 1 micron or larger from the water that passes through it.
 

Absolute, theoretically, means that the filter will reject virtually all of the particles of the given size. The usual expectation is a 3-log rejection–or 99.9%. Absolute ratings are usually used for the tightest filters and for purposes where efficiency really matters. For example, if a filter maker promises removal of E. coli, more or less 85% efficiency isn’t good enough. If you’re going to trust your life to the filter, you expect an absolute 3-log or 4-log rating at the very least.
 

The problem with the absolute vs. nominal system is that there is really no universal standard that assures uniformity. Some makers of filters for non-critical applications, for example, might consider 70% rejection suitable for a nominal filter. Definitions vary from one manufacturer to another, and there is really no way for the end user to verify the claim. 
For most common filtration issues filters rated as “nominal” are used.  For example, a nominal 5 micron sediment filter is a standard size used in much residential water treatment.
 
 
Keep in mind that tighter is not always better.  The lower the micron rating of a filter, the more it restricts flow.  An absolute 1 micron filter is normally not a good choice for a residential  whole house sediment filter because there will be too much pressure loss.  If you put in a filter to remove sand, a filter with a low micron rating is not only unnecessary, but it will also become clogged much faster than a looser filter. 
 
 
 

Which drink is best for hydration? Hint: It isn’t water

by Lisa Drayer


Pure Water Gazette Note: Keep in mind that fluids that you take into your body do more than "hydrate." Therefore, you should think more than twice about choosing cow's milk over water as a regular strategy to achieve more perfect "hydration." There are, after all, issues like cholesterol, bone problems, and mucous in the respirtory tract to consider if you start drinking quarts of milk every day in order to be better "hydrated." 
 
 
 

When you’re thirsty and in need of a drink, which beverages are best at keeping you hydrated? Sure, you can always reach for a glass of water — but plain H20 isn’t the most hydrating beverage around, according to a study from Scotland’s St. Andrews University that compared the hydration responses of several different drinks.The researchers found that while water — both still and sparkling — does a pretty good job of quickly hydrating the body, beverages with a little bit of sugar, fat or protein do an even better job of keeping us hydrated for longer.
 
The reason has to do with how our bodies respond to beverages, according to Ronald Maughan, a professor at St. Andrews’ School of Medicine and the study’s author. One factor is the volume of a given drink: The more you drink, the faster the drink empties from your stomach and gets absorbed into the bloodstream, where it can dilute the body’s fluids and hydrate you.
 
 
Milk is more hydrating than water


The other factor affecting how well a beverage hydrates relates to a drink’s nutrient composition. For example, milk was found to be even more hydrating than plain water because it contains the sugar lactose, some protein and some fat, all of which help to slow the emptying of fluid from the stomach and keep hydration happening over a longer period.Milk also has sodium, which acts like a sponge and holds onto water in the body and results in less urine produced.
 
The same can be said for oral rehydration solutions that are used to treat diarrhea. Those contain small amounts of sugar, as well as sodium and potassium, which can also help promote water retention in the body.“This study tells us much of what we already knew: Electrolytes — like sodium and potassium — contribute to better hydration, while calories in beverages result in slower gastric emptying and therefore slower release of urination,” said Melissa Majumdar, a registered dietitian, personal trainer and spokeswoman for the Academy of Nutrition and Dietetics who was not involved in the study.
Sugar in moderation


But here’s where it gets tricky: Beverages with more concentrated sugars, such as fruit juices or colas, are not necessarily as hydrating as their lower-sugar cousins. They may spend a little more time in the stomach and empty more slowly compared to plain water, but once these beverages enter the small intestine their high concentration of sugars gets diluted during a physiological process called osmosis. This process in effect “pulls” water from the body into the small intestine to dilute the sugars these beverages contain. And technically, anything inside the intestine is outside your body.Juice and soda are not only less hydrating, but offer extra sugars and calories that won’t fill us up as much as solid foods, explained Majumdar. If the choice is between soda and water for hydration, go with water every time. After all, our kidneys and liver depend on water to get rid of toxins in our bodies, and water also plays a key role in maintaining skin’s elasticity and suppleness. It’s the cheapest moisturizer you’ll find.While staying hydrated is important — doing so keeps our joints lubricated, helps prevent infections, and carries nutrients to our cells — in most situations people don’t need to worry too much about how hydrating their beverages are.“If you’re thirsty, your body will tell you to drink more,” Maughan said. But for athletes training seriously in warm conditions with high sweat losses, or for someone whose cognitive function may be negatively impacted by working long hours without beverage breaks, hydration becomes a critical issue.
 
 
Can beer and lattes keep me hydrated?


Alcohol acts as a diuretic, which causes you to pass more urine, so when it comes to alcoholic beverages hydration will depend on a beverage’s total volume. “Beer would result in less water loss than whiskey, because you are ingesting more fluid with beer,” Maughan said. “Strong alcoholic drinks will dehydrate, dilute alcoholic drinks will not.”When it comes to coffee, how well your java hydrates you will depend on the amount of caffeine you consume. A regular coffee with about 80 milligrams of caffeine — roughtly what you would find in 12 oz. of Folgers’ house blend – would be pretty much as hydrating as water, according to Maughan’s research.Consuming more than 300mg of caffeine, or about 2-4 cups of coffee, could cause you to lose excess fluid as the caffeine causes a mild, short-term diuretic effect. This is more likely to happen with someone who doesn’t typically consume caffeine, and it could be offset by adding a tablespoon or two of milk to your cup of joe.
 
 
CTV News

 
 
 

How Long Do Water Filters Last?

 
Probably you have seen an ad for a small, one-cartridge “ten stage” water filter that promises to remove chlorine, lead, pesticides, herbicides, VOCs, fluoride,  and “pharmaceuticals,” and to “last for 10,000 gallons.” This advertising claim is actually true. But at the same time, it is a big lie. A really big lie.
 
 
The intent is to imply that the filter will remove fluoride, VOCs, and all the other heavy contaminants listed “for 10,000 gallons.” But what “lasts for 10,000 gallons” really means is that it won’t fall apart and that it may even be removing some chlorine after 10,000 gallons. While it may “remove fluoride” for the first few gallons, it really doesn’t contain enough fluoride media to last past the original cartridge rinse. The trick is in the words.  It’s true that it “removes fluoride” and that it “lasts for 10,000 gallons,” but it certainly doesn’t remove fluoride for 10,000 gallons.
 
 
Even single media filters, like carbon blocks, have greatly different capacities for various contaminants that they treat.  Filter carbon is a very effective treatment–the best, in most cases–for a large majority of water contaminants, but in almost every case carbon filters treat chlorine much longer than they effectively treat more difficult contaminants.
 
 
For example, the manufacturer of one superb carbon block filter states the capacity of its 2.5″ X 10″ cartridge for removing chlorine as 20,000 gallons @ 1 gallon per minute. For removal of VOCs, however, the claim is for only 500 gallons at the reduced flow rate of 0.5 gallons per minute.
 
 
It is a mistake to assume, in other words, that the filter will remove VOCs as long as it will treat chlorine. If chlorine removal and taste/odor improvement are the only goals, then the filter can be used to its full chlorine capacity; but if you really need serious removal of specific contaminants, you should find out the cartridge’s capacity for the specific item you’re targeting and replace the cartridge accordingly.
 
You should also notice that flow rate matters–a lot–and that if you want a faster flow rate, you need a larger filter.
 
 

Boil Water Alerts and Backwashing Whole House Filters

There is a lot of advice about what to do with a drinking water filter after your city issues a boil water alert. The advice ranges from simple to way over-complicated. However, what you should do to protect a whole house backwashing filter during and after a boil water alert is not so easy to find.
 
 
The following isn’t designed to be the official last word on the subject, but here’s my method. 
 
 
1. As soon as you are notified of the boil water alert, put the filter in by-pass mode so that contaminated water will not enter the filter.  Leave it there until the alert is over.
 
 
2. When normal service is restored, put the unit back into service position and do a full manual regeneration with the treated city water.
 
 
3. Return the filter to by-pass position and leave it for at least a couple of days so that chlorine or chloramine can disinfect the piping downstream of the filter. Use the water as normal so that the disinfectant can clean out the house lines downstream of the filter. Make it a point to run some water through every outlet in the home.  See that the pipes get a good rinse.
 
 
4. Put the filter back into service position, do another manual regeneration, then start using the water as usual.
 
 
The two articles above are from the Pure Water Gazette's "Water Treatment 101" series. The complete Water Treatment 101 series, which goes back to 2012, contains numerous articles meant to provide practical information about finding and maintaining home water treatment devices. You'll find the full series by taking the link provided above.

 
 
 
 

 

Water News for June 2025

 

40% of Glaciers Are Doomed 
 

Almost 40% of glaciers in existence today are already doomed to melt due to climate-heating emissions from fossil fuels, a study has found. The loss will soar to 75% if global heating reaches the 2.7C rise for which the world is on track. The massive loss of glaciers would push up sea levels, endangering millions of people and driving mass migration.  The Guardian.
 

Crypto Outbreak in Devon

BBC reported that in Devon a cryptosporidium outbreak, which contaminated the local water supply and lead to hospitalizations and more than 100 reported cases of illness, caused significant financial loss to the water supplier. BBC.
 
 
Do Not Eat Warnings for Fish in Michigan
Amid evidence that PFAS is far more dangerous than previously thought, state officials have revised statewide guidelines for eating contaminated fish.
 
 
Michigan health officials have dramatically reduced the amount of PFAS-tainted fish they consider safe to eat, tripling the number of water bodies where anglers are warned against eating their catch.
Ninety-eight water bodies are now subject to “do not eat” advisories because fish are contaminated with the so-called “forever chemicals,” up from 33 last year. Hundreds more advisories suggest that Michiganders limit meals of certain fish species to anywhere from 16 servings a month to six a year.
 
 
Officials with the Michigan Department of Health and Human Services announced the change Monday while publishing the annual Eat Safe Fish Guide, a document that identifies waterways where fish are contaminated with unsafe levels of toxic chemicals. Bridge Michigan
 
 
Diesel Spill in Baltimore
 

A leak of some 2000 gallons of diesel at Johns Hopkins Hospital in East Baltimore traveled through storm drains for more than a mile to the harbor. The impact on drinking water quality is still unclear. Newsweek  
 
 
Salmonella Traced to Cucumbers Grown in Contaminated Irrigation Water
 

A salmonella outbreak tore through the country last spring and summer, infecting more than 550 people and sending 155 to the hospital.
 
 
The likely culprit wasn’t raw eggs or undercooked chicken but an innocuous salad staple: cucumbers.
 
 
One year later, cucumbers are once again making people sick — and federal officials say that one of the same Florida farms is once again involved. Forty-five people in 18 states recently contracted salmonella in an outbreak linked to cucumbers from Bedner Growers in Palm Beach County, setting off a widespread recall that has affected everything from California rolls sold at Target to banh mi sandwiches served at a North Carolina high school.
 
 
The Food and Drug Administration has yet to explain how the cucumbers linked to the current outbreak became contaminated; the investigation is ongoing. But last year, the agency found that Bedner Growers had used untreated canal water for irrigation — and that the water was contaminated with one of the salmonella strains that had made people sick.
 
 
Cucumbers and other fresh produce may be a surprising source of salmonella, which can cause diarrhea, stomach cramps and fever, as well as more serious health problems that can turn fatal. Heat from cooking can kill the bacteria, but fruits and vegetables that are eaten raw, like cucumbers, can be unsafe once they are contaminated. That means it’s particularly important to protect fresh produce from pathogens lurking in water used for irrigation or washing.   NBC News.   
 
 
Contaminated Water Blamed for Elephants’ Death

The unexplained deaths of hundreds of elephants near watering holes across the Okavango delta in May 2020 alarmed conservationists. Nearly five years later, scientists finally published a paper indicating what they believe to be the reason behind the deaths: toxic water caused by an algal bloom.  The Guardian  
 
 
National Hydration Day

National Hydration Day was June 23. As far as we can determine, not a single business or government office anywhere closed to honor the holiday.
 
 
The World’s Worst Case of PFAS Contamination

When residents in a small Swedish town discovered their drinking water contained extremely high levels of PFAS, they began blood testing. They had no idea what it would mean for their health and their children’s future.  Read the Guardian report:   Poison in the water: the town with the world’s worst case of forever chemicals contamination.
 
 
Water Treatment Employee Dies in Water Tank

In Ottawa County Ohio, a water treatment employee was found dead inside a water tank, prompting a boil advisory in multiple areas in the state.
 
 
According to WTOL, citing a report from the Ottawa County Sheriff’s Office, authorities responded to the Ottawa County Regional Water Treatment Plant on Monday and discovered a night shift employee floating face down in a tank filled with water.  WKRC – TV
 
 
Expectant Mothers Advised to Drink Filtered Water
 

Pregnant women have been advised to use water filters by experts who spoke to Newsweek after a study found levels of arsenic in water systems considered safe are impacting birth outcomes.
 
A national study led by researchers at Columbia University evaluated risks from 13,998 pregnancies across 35 cohort sites participating in the National Institutes of Health’s Environmental influences on Child Health Outcomes (ECHO) program, and published its findings on the medical journal site JAMA Network last week.
 
The researchers discovered that prenatal exposure to arsenic was associated with a higher likelihood of babies being born preterm with lower birth weights, factors that they said are important “predictors of infant mortality and morbidity across the life span.”
 
This was the case even at the level of exposure the Environmental Protection Agency (EPA) currently deems safe, 10 micrograms per liter, a regulation that was established in 2001 and has not been changed since.  Newsweek. Full article.
 
 
 
 
 
 
 
 

Basic Heavy Duty Whole House Cartridge Filters

 
 
 
 
Tough, versatile 20-inch “Big Blue” housings can be used alone or in a variety of combinations to meet virtually any “whole house” filtration situation. They are simple, durable, easy to install, and easy to service. They use standard-sized cartridges so replacements are easy to find.
 
 
Parallel installation, as pictured below, make them suitable for even large homes.  Installing in parallel greatly reduces pressure loss, enhances the effectiveness of the unit,  and extends the life expectancy of the cartridges.
 
 
Cartridge filters are much easier to maintain than tank-style filters.  As for installation, they are compact in size and do not require electricity or connection to a drain.  Most require only an annual cartridge change, which can usually be done by the homeowner.
 
 
The  chart below shows sizing suggestions for whole house filtration for water that is treated with chlorine or chloramine.  Chloramine units require more expensive cartridges than than the unit treating chlorine. 
 
 
Description
Application
To Determine Pricing
System 1. One 4.5″ X 20″ 5 micron sediment filter plus one 4.5″ X 20″ high performance carbon filter. Homes with 1 to 3 people. Flow rates to 5 gpm. Price is the same as WH103 on this page.
System 2. One 4.5″ X 20″ 5 micron sediment filter plus two 4.5″ X 20″ carbon filters installed in parallel. Homes with up to 5 people. Flow rates to 10 gpm. Price is the same as one WH103 and one WH102 on this page.
System 3. One 4.5″ X 20″ 5 micron sediment filter plus three 4.5″ X 20″ carbon filters installed in parallel. Homes with up to 8 people. Flow rates to 15 gpm. Price is the same as one WH103 and two WH102 on this page.
 
 
 
 
Basic Housing and Bracket Setup. The Housing is available for 3 pipe sizes–3/4″, 1″, or 1.5″.  This very versatile “Big Blue” housing will accept any standard 4.5″ X 20″ cartridge. It can be used for sediment cartridges, carbon cartridges, or “media” cartridges for special purposes like iron removal or pH increase.
 
 

 
 
 

Basic Parallel Arrangement for Sediment Filter followed by two Carbon Filters installed in parallel. This arrangement increases service flow rate, extends cartridge life, and greatly increases effectiveness. 
 
 
 

 

 

Aeration Overview

Aeration is an effective chemical-free method of preparing well water containing iron and hydrogen sulfide for filtration. Exposure to air “oxidizes” the contaminant to a filterable form (ferric iron or elemental sulfur), then an appropriate filter removes the contaminant from the water.
Closed tank aeration for residential treatment is available in several formats. The least expensive, though not necessarily the simplest, uses a small venturi that is installed in the water line itself in front of the well’s pressure tank. As water fills the tank, air is literally sucked into the water stream via the venturi. A small treatment tank where “oxidation” occurs follows the pressure tank. The water then goes to a free-standing filter for final filtration.
 
 
A much more aggressive treatment uses a small air compressor, or “air pump,” that injects air into a treatment tank. When water enters the tank it falls through a pocket of compressed air where rapid oxidation occurs. The water then passes on to a filter tank for final removal of the contaminant.
 
 

A Small Compressor Powers the “AerMax” System
 

Single tank units are the simplest form of aeration treatment. Single tank systems perform the aeration and filtration in a single tank. Water enters the tank, falls through a pocket of compressed air, then is filtered by the media contained in the lower 2/3 of the tank. Single tank units need no pump; they bring in air during the nightly regeneration performed automatically by the control unit.

More Information

PWO0721
 
 

Water Tests for Your Home

 

The exceptional value of a good water test and how to understand what it means

For some years we been offering high quality water tests to our customers provided by National Testing Laboratories of Cleveland. General information and pricing for these excellent tests can be found here on our website.
 
The lab offers a comprehensive test (Watercheck) as well as specific city water and well water versions. A number of individual analytes not included on the standard tests (iron bacteria, for instance) can also be added if needed.
 
How It Works

The test is ordered from our website. Upon receipt of the order, we send you a test kit. You then take samples of  your water, as directed in the kit, and overnight the samples to the NTL laboratory in Cleveland. The lab reports the results to you in an easy-to-understand format and also sends us (Pure Water Products) a copy of the results so we can help with interpretation and recommendations for treatment if you ask us.
 
The lab also makes available valuable online information to help with understanding the test result. Here are a couple of valuable reference guides provided.
 
A comprehensive chart giving detailed information about water contaminants such as commons sources of the contaminant in drinking water, the allowable amounts, the treatments required for removal with very helpful color coding for classification of the contaminant.
 
An informative brochure telling how to deal with water issues revealed by testing.
 
Please visit our website for more information:
 
Professional Water Test (from National Test Laboratories)  — Information and ordering from our website.
 
 
 
 
 
 
 
 
 
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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