Pure Water Occasional, February 3, 2018
In this Groundhog Day Occasional you'll read about the top water stories of the past year, water's role in the human brain, adding minerals back into RO water, the uses of various ion exchange resins, how nitrates get into water, and how fluoride is or isn't taken in through the skin. And, as always, there is much, much more.
Because weather plays such an important role in water quality, Groundhog Day should rank right up there with National Garden Hose Day as one of the planet’s most important holidays. Water quality and availability are only partially within our control.
Groundhog Day started in Europe as a Christian holiday involving candles, Candlemas Day. As with other holidays, its significance has been trivialized.
Because of the Bill Murray movie, most Americans believe that there is only one weather-forecasting Groundhog. Actually, spread across the US and Canada there are many places that honor their Groundhog as the True Groundhog. The commemorative statue above honors the late Wharton Willie of Wharton, Ontario. Whartonites consider Punxsutawney Phil a furry imposter.
So as we contemplate the prognostications of the Groundhog of our choice, we should remind ourselves that water is a gift to be regarded with reverence and that what is given can also be taken away.
Let the Groundhog Day festivities begin!
Water and the Human Brain
As a whole, the human brain is composed of roughly 73% water.
Most of the brain is made up of two kinds of tissue: gray matter and (myelinated) white matter. The gray matter is about 80% water, while the lipid-rich white matter has about 70% water content.
Also, on average, the water content of a female brain’s gray matter is 1.2% higher than that of its male counterpart.
Your brain’s high water content is among the many reasons it’s essential to drink enough water each day, and part of the reason dehydration impairs your focus, memory and mood.
Upgrade RO with Remineralizing Cartridge
There is increasing interest in adding mineral content back into reverse osmosis water. Raising the mineral content also raises the pH, and according to many, improves the taste of low-pH RO water.
This can be accomplished easily by adding a simple post-filter containing calcite or calcite combined with a small amount of Corosex (aka FlowMag). Both are standard water treatment minerals available in NSF Standard 60 brands that are regularly used to raise pH of acidic well water and as post-treatment for “whole house” reverse osmosis units. Calcite is natural calcium carbonate made from crushed granite and FlowMag is magnesium oxide. They add back to the water natural calcium and magnesium plus whatever trace minerals are present in the natural sources.
The picture above shows the easiest way to add a calcite filter. The inline filter on the very top is a calcite/coconut shell carbon postfilter added after the unit’s regular post filter (white housing). It provides some extra carbon, a bump in pH, and added minerals. It makes excellent tasting water, is inexpensive, and is easy to replace. Total cost of the cartridge, the clips to hold it, and the fittings is around $30.
Another way to add a remineralizing stage to your existing RO unit is to add a free-standing full-sized calcite/Corosex cartridge after your present post-filter. With this method you simply add the remineralizing filter into your faucet line between the current post-filter and the faucet. The remineralizing unit shown below connects easily with quick connect fittings in the same size as your present faucet line.
The round number cost of adding the free-standing add-on calcite filter, for filter, bracket, fittings, and one cartridge, is about $60.
Nitrate Contamination of Drinking Water is Sure to Increase
Gazette Note: This important study demonstrates the long-term implications of our excessive use of nitrogen fertilizers. Nitrate contamination of drinking water is a serious issue, and the study shows that what we do now pollutes the drinking water of future generations. –Hardly Waite.
Nitrogen fertilizer applied to crops lingers in the soil and leaks out as nitrate towards groundwater much longer than previously thought, scientists in France and at the University of Calgary discovered in a new study.
Thirty years after synthetic nitrogen fertilizer had been applied to crops in 1982, about 15 per cent of the fertilizer nitrogen still remained in soil organic matter, the scientists found.
After three decades, approximately 10 per cent of the nitrogen fertilizer had seeped through the soil towards the groundwater and will continue to leak in low amounts for at least another 50 years.
Nitrate is one of the most common groundwater contaminants in rural areas. It is regulated in drinking water primarily because excess levels can cause methaemoglobinemia, or “blue baby syndrome,” which decreases the ability of blood to carry oxygen around the body.
The study was led by researcher Mathieu Sebilo at the Universite Pierre et Marie Currie in Paris, France, and by Bernhard Mayer in the University of Calgary’s Department of Geoscience, and included several research organizations in France.
Their paper, “Long-term fate of nitrate fertilizer in agricultural soils,” was published recently in the Proceedings of the National Academy of Science of the United States of America.
The findings show that losses of fertilizer nitrogen towards the groundwater occur at low rates but over many decades, says Mayer, professor of geochemistry and head of the Applied Geochemistry Group.
That means it could take longer than previously thought to reduce nitrate contamination in groundwater, including in aquifers that supply drinking water in North America and elsewhere, he says.
“There’s a lot of fertilizer nitrogen that has accumulated in agricultural soils over the last few decades which will continue to leak as nitrate towards groundwater,” Mayer says.
Canada and the U.S. regulate the amount of nitrate allowed in drinking water. In the 1980s, surveys by the U.S. Environmental Protection Agency and the U.S. Geological Survey showed that nitrate contamination had probably impacted more public and domestic water supply wells in the U.S. than any other contaminant.
Mayer is an internationally recognized expert in the use of stable isotopes to track contaminants in the environment.
The French-University of Calgary study is the first that tracks, using stable isotope “fingerprinting,” the fate of fertilizer nitrogen remaining in a soil zone over several decades. The research team used a stable isotope of nitrogen, N-15, as a tracer to track fertilizer nitrogen applied in 1982 to sugar beet and winter wheat crops on a pair of two-metre-square plots at a site in France.
Over the 30-year study, the researchers measured the amount of N-15 labeled fertilizer nitrogen taken up by plants and they quantified the amount of fertilizer nitrogen remaining in the soil.
The novel aspect of their study was that they subsequently determined the long-term fate of this fertilizer nitrogen ‘pool’ retained in the soil. Their measurements of seepage water from locations two metres deep in the soil revealed the amount of fertilizer nitrate leaking towards the groundwater.
The team found that 61 to 65 per cent of the N-15 fertilizer applied in 1982 was taken up by the sugar beet and wheat plants over the 30-year study.
However, 32 to 37 per cent of the fertilizer nitrogen remained in the soil organic matter in 1985 or three years after application, while 12 to 15 per cent still lingered in the soils after three decades.
Between eight to 12 per cent of the fertilizer nitrogen applied in 1982 had leaked in the form of nitrate toward groundwater during the 30 years, and will continue to leak at low rates “for at least another five decades, much longer than previously thought,” the study says.
The scientists predict that about 15 per cent of the initially applied fertilizer nitrogen will be exported from the soils towards the groundwater over a time span of almost one century after the 1982 fertilizer application.
“If nitrate keeps leaking into the groundwater for decades after fertilizer application, then it will be more difficult to reduce nitrate contamination of groundwaters in a timely fashion,” says Mayer.
Mayer speculates that if the same research were done in Alberta, the findings would be similar in terms of fertilizer uptake by plants and nitrogen retention in the soils, although Alberta’s comparatively dry climate and different geology might slow the rate of nitrate seeping towards the groundwater.
Common Uses of Ion Exchange Resins in Water Treatment
Ion exchange resin has been an effective water treatment tool for many years. The most common use, by a long way, is for water softening. Ion exchange resins, however, have many other less frequently used applications. Resins are used to reduce arsenic, nitrates, uranium, perchlorate, and more. They can also “deionize” water completely, removing the full mineral content.
Cation resins exchange positive ions and Anion resins treat negative ions.
Here’s a chart showing types of resins and many of their uses:
|SAC-Strong Cation Acid
||Water softening, iron reduction, barium and radium removal.
||Exchanges for sodium ions.
|WAC – Weak Acid Cation
||Softens water (removes calcium and magnesium), reduces TDS mildly, and reduces alkalinity.
||Has the often undesirable effect of lowering pH.
|SBA – Strong Base Anion
||Reduces nitrates, arsenic, perchlorate, TOC (Total Organic Carbon), uranium. Can also be used as an antimicrobial disinfectant.
||Special grades with selectivity built in are often used.
|SBC and SBA together.
|| SAC and SBA resins employed in combination either individually or mixed together can be used to reduce minerals and TDS in water.
||The process is known as deionization (DI) or demineralization. The media can be placed in the same tank or in separate tanks.
Indebted to “Ion Exchange Resins and Their Applications,” Water Technology, Nov. 2015.
Is Fluoride Absorbed Through the Skin?
by Emily McBroom and Gene Franks
We discovered an amazing fact about municipal water fluoridation.
Although this seems incredible, city water suppliers, at the recommendation of government health officials and independent groups like the American Dental Association, have been dosing fluoride into municipal water supplies for several decades although no one has yet bothered to find out to what extent fluoride in water is absorbed through the skin. Although there have been a few studies buried deep in academic archives that dance around the subject of human uptake of fluoride through the skin, there is certainly no clear-cut understanding of the issue as there is, for example, with the dermal uptake of chlorine.
The absorption of chlorine through the skin has been studied and well established. Studies we’ve done regarding the uptake during bathing of contaminants like lead and arsenic have yielded a lot of information. Not so with fluoride.
Although we did some general searching, we spent a lot of time reading the references from the website of an active and research-oriented anti-fluoridation organization, the Fluoride Action Network (FAN), with the assumption that if evidence exists that fluoride is taken up through the skin an organization looking for reasons to end fluoridation of tap water would find it. Searches of the FAN site and general searches of the web, however, reveal that specific studies that focus on absorption of fluoride through the skin do not exist. Most studies of contact of fluoride on human skin focus on hypersensitivity to fluoride through ingestion and topical use inside the mouth.
One study indicates, for example, that fluoride can penetrate the mouth’s mucous membrane but does not cross the skin barrier. There are studies of the reaction of the skin to contact with fluoride such as contact dermatitis, inflammation, skin lesions, and rashes. There are studies documenting human hypersensitivity to fluoride and many studies about allergic reactions to fluoride. There’s a scholarly study showing that fish (in this case Siberian sturgeon) take up F- directly from water and it is extremely detrimental to their health. There are studies involving application of fluoride to the shaved leg of a rat and an ambitious study on the question of permeability of fresh and frozen human skin and fresh and frozen pig skin of anions including fluoride.
Most of this seems only remotely related to the real questions we should be asking about how much fluoride does a real, live human take in by bathing or showering with fluoridated tap water. We know that the fluoride load on the human body is cumulative. Fluoride is stored in the bones and teeth. How much fluoride does a small child accumulate by playing for hours on a summer afternoon in a pool filled with fluoridated tap water? How much fluoride does a teenager accumulate through the skin and through the air during an hour-long shower? How much fluoride does a competitive swimmer take in during a long practice session in fluoridated pool water?
Although we find no studies that address these questions, there are some publications that make general assumptions with little research to back them up.
For example, there is a reassuring essay by the European group The Scientific Committee on Health and Environmental Risks (SCHER). SCHER examines in detail the amount of fluoride one might get from drinking water, swallowing toothpaste and other oral means of ingestions, but passes the dermal absorption issue off lightly:
No experimental data on the extent of dermal absorption of fluoride from dilute aqueous solutions are available. As fluoride is an ion it is expected to have low membrane permeability and limited absorption through the skin from dilute aqueous solutions at near neutral pH (such as water used for bathing and showering). This exposure pathway is unlikely to contribute to the fluoride body burden.
On the possibility of inhalation during showering, SCHER says:
No systematic experimental data on the absorption of fluoride after inhalation are available. A few older occupational studies have shown uptake of fluoride in heavily exposed workers from fluoride-containing dusts, but it is unlikely that inhalation exposure will contribute significantly to the body burden of fluoride in the general population
Similarly, a publication of the New Hampshire Dept. of Environmental Service seems to say that fluoride can be taken in through the skin and through breathing but that in the real world this isn’t a big problem:
Fluoride can be absorbed from the gastrointestinal tract after ingestion, following inhalation, and through the skin. Soluble forms of fluoride, such as those added to fluoridate water, have been found to be absorbed at an efficiency of 90 percent or greater. Of the ingested fluoride that remains in the body, 99 percent is incorporated into the bones and teeth. Inhalation and skin absorption can be significant for some occupational exposure situations, but are not important exposure routes for fluoride in drinking water.
We take that by “drinking water” they mean fluoridated tap water.
Since there is no hard evidence on the uptake of fluoride through the skin, at least none that we can find, we can rely only on common sense. Since fluoride is a potent poison that can kill and disable when ingested in amounts a bit larger than the accepted public water dosage, it seems implausible that significant quantities of fluoride are being taken in through the skin via exposure to fluoridated water. If fluoride were entering the body via the skin in large quantities, it would become obvious quickly in the form of fluoride poisoning in high risk groups like swimmers, people who take long showers and baths, and those who have prolonged workplace exposure to fluoridated water.
We are, therefore, sticking with our own belief that fluoride is a significant issue when taken in by mouth but not so much when exposure comes via bathing or breathing.
From a practical standpoint, we take the same position that we do on lead and arsenic. We do not recommend “whole house” fluoride treatment. We feel that fluoride is a drinking water issue and that residential users should use a proven drinking water fluoride treatment–undersink reverse osmosis is the best–and make a point of drinking water only from their water treatment system. Whole house fluoride treatment is both impractical and unnecessary.
The leading water news stories of the past year
2017 was an eventful year. We saw several “top water stories” lists. What follows is Water Online's choice for the top three water treatment stories of the year.
1. Awareness Of PFC Contamination
Just as the country’s lead contamination crisis dominated mainstream and industry headlines alike in 2016, drinking water contamination caused by perfluorinated compounds (PFCs) was among the biggest news for the treatment community in 2017.
Lead contamination has stemmed from the presence of corroded lead service lines in much of the country’s infrastructure, while the main sources of PFC contamination appear to be firefighting foam used by the Air Force and Navy and through the manufacture of industrial products such as Teflon.
The issue found its way into consistent news coverage thanks to concerned community members in Hoosick Falls, NY. Once the red flag around the health consequences of PFC-contaminated water was raised, communities all over the country found themselves to be similarly affected. Communities in Pennsylvania, Rhode Island, Washington, and elsewhere have all raised their own concerns around the issue.
While the U.S. EPA does not have any formal regulations limiting the presence of perfluorooctanoic acid (PFOA) or perfluorooctanesulfonic acid (PFOS), the two primary PFCs found in drinking water, the agency has issued a health advisory intended to guide utilities on just how dangerous they can be. The agency noted that exposure to PFOA and PFOS can result in development effects to fetuses, cancer, liver effects, immune effects, thyroid effects, and other health consequences. It sets a combined concentration of the two at 70 ppt, though the state of Michigan has proposed the much stricter limit of 5 ppt.
As the EPA balances the possibility of instituting stricter regulations on PFCs, it has launched a “cross-agency” effort to help address contamination and has become involved in some state-led investigations. Until further federal action, however, local municipalities are left to deal with the issue on their own.
2. The Surge Of Fracking
While the practice of hydraulic fracturing, commonly known as fracking, did not emerge in 2017, it certainly saw an uptick.
A combination of growing oil prices and encouragement from the current political climate has seen domestic fracking production increase steadily all year and some federal estimates project all-time highs for barrels produced per day in 2018. As the fracking production rises, so to do the produced water treatment technologies that can enable it.
Hydraulic fracturing works by using high-pressure water to drill through rocks and access oil deposits beneath them. The wastewater that stems from this process is highly contaminated and must be treated to at least some degree before it can be returned to source bodies. Increasingly, that treatment happens onsite, utilizing some of the latest decentralized treatment technology to have emerged. New projects launched this year leveraged solar power and cutting-edge filter technology to help fracking operations handle their wastewater. The solutions encouraged by the rise of fracking in 2017 could very well yield new technologies suited for treatment operations all over the country.
But along with the rise in fracking popularity and technology, the debate over the threat posed to source and drinking water quality intensified as well. The U.S. EPA has at times conflicted itself over its take on the safety of fracking, including a report that it kept hidden a report on potential health dangers. This year also had its fair share of reports that the practice poses no threat to drinking water safety.
With the practice poised to grow in 2018, the water quality debates it inspires will grow as well, as too will the novel treatment technology solutions it inspires.
3. The New-Look EPA
When Donald Trump was elected president in late 2016, it took much of the country by surprise. Throughout his tenure in 2017, it became clear that surprises were just about the only thing one could rely on when it came to his administration.
Trump’s departure from nearly every policy and stance established during the Obama administration has undoubtedly made its way to the EPA. As such, it has had a profound effect on the drinking water and wastewater regulations in this country and the work of treatment utilities therein.
The new-look EPA, headed by former Oklahoma Attorney General Scott Pruitt, can be summed up as one that is attempting to clear regulatory red tape for the nation’s businesses, which generally prefer fewer restrictions on their environmental practices. While this means that it is easier for treatment operations to adhere to their regulatory requirements, it can also pose challenges for keeping drinking water and source water safe.
For instance, the agency has been working hard to undo the Obama era establishment of the Waters of the U.S. (WOTUS) rule, which sought to clarify which source waters fall under federal jurisdiction. Trump has issued an executive order looking to rescind and replace the Clean Water Rule, which contains WOTUS.
The EPA has also been cutting back on staff, scientists, and budget, all in an attempt to reshape the agency to be less inefficient and to clear the way for progressive industrial practices.
It’s anyone’s guess what the Trump administration has in store for 2018, but it’s clear that the new direction of the EPA will continue to have effect on the country’s treatment operations.
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Thanks for reading and be sure to check out the next Occasional!