Pure Water Occasional, May 22, 2020 |
Recent news has, of course, been dominated by the coronavirus. As regards drinking water, the main thing you need to know is that the virus isn't a drinking water issue. Not yet, anyway.You don't need a special filter, or any filter, to remove it from your water because it isn't there.
Something almost everyone has noticed is that as human activity has decreased during the shutdown, some things have gotten a lot better. Air quality is remarkably better almost everywhere, and canals and beaches are cleaner. Philadelphia Inquirer.
PWP Shutdown Schedule
Pure Water Products' online business is doing business as usual during the national shutdown. We are offering the same service as before for internet customers, including phone and email product support. Since we've spread our staff out, we may be a little slower shipping or responding to calls and emails.
Locally, we've closed down our in-store services and are not doing service calls or installations. Also, we have no scheduled Saturday phone support hours, though if you email, or call and leave a message, we'll respond promptly.
Surface Albedo: A New Concern in Flow Reduction of Rivers
A recent US Geological Survey (USGS) study used a new model and satellite-based observations to reproduce and explain the mechanism of flow reduction: Surface albedo (reflectivity) determines how much solar radiation is absorbed by the land surface and available to drive evapotranspiration. Albedo is highly sensitive to snow cover, which is an efficient reflector of solar radiation. As temperatures rise, more precipitation falls as rain instead of snow, and what snow does fall melts earlier in the year. The loss of snow exposes the land to increased solar radiation. The absorbed radiative energy is dissipated by further heating of the lower atmosphere and increased evaporative cooling. The increased evaporation consumes water that would otherwise run off into the river, reducing the amount of streamflow. So now you know. (How this is affecting the Colorado River.)
A new study done at Washington State University estimated that every day about eight trillion pieces of microplastics go through wastewater treatment plants and end up in the aquatic environment. These little bits of plastic can come from the degradation of larger plastics or from microbeads that are used in personal care products. A recent study showed that more than 90 percent of tap water in the U.S. contains nanoscale plastics that are invisible to the human eye. Many of these eight trillion pieces of microplastic, of course, pass through humans on the way to the wastewater treatment plant.
The map above, from the National Weather Service, shows areas likely to experience significant flooding this spring. Flooding is especially ominous during the coronavirus pandemic when emergency resources are already overtaxed. Full story.
Health officials have been telling people for weeks to wash their hands thoroughly to help prevent the spread of coronavirus. That’s not always an easy task on the Navajo Nation, where 30% of residents on the vast reservation don’t have running water in their homes. Story from The Durango Herald.
The new Google data center being built in water-starved Mesa, Arizona is guaranteed one to four million gallons of water per day. Bloomberg.
Risk of COVID-19 exposure from packages is ‘small and manageable’
The risk of being exposed to COVID-19 from a delivered package, restaurant takeout, or groceries from the market is low, according to Joseph Allen, assistant professor of exposure assessment science at Harvard T.H. Chan School of Public Health.
In a March 26, 2020, op-ed in the Washington Post, Allen examined the “causal chain,” or series of events, that would need to exist in order for someone to become sick from handling a package. Allen noted that while recent research has shown that the virus can be detected on some surfaces for up to a day, “the reality is that the levels drop off quickly.”
Allen emphasized that people should remain vigilant about washing their hands, and, when shopping, keep six feet from other customers and store employees.
“If you take basic precautions, including washing your hands frequently, the danger from accepting a package from a delivery driver or from takeout from a local restaurant or from buying groceries is de minimis,” he wrote. “That’s a scientific way of saying, ‘The risks are small, and manageable.’”
Domestic Water Use Has Grown by 600% Over the Past 50 Years
Humanity’s thirst for freshwater has more than doubled since the 1960s, keeping pace with growing populations and economies. One-quarter of the world now faces extremely high water stress, where more than 80% of the available supply is withdrawn every year. While agriculture and industry withdraw the overwhelming majority of the world’s freshwater (70% and 19%, respectively), demand from households is also rising precipitously. New data shows that domestic water demand grew 600% from 1960-2014, at a significantly faster rate than any other sector. More.
A new bill from Senate Democrats would roll out $20 billion in funding to remove PFAS from water. The bill, Providing Financial Assistance to States for Testing and Treatment Act of 2020, is also known as the PFAS Testing and Treatment Act. The bill would expand the reach of existing water programs run by the U.S. EPA and increase the funding of various grant programs, while allowing that money to be used to remove PFAS from water. The funds could be used by major water systems or even homeowners who need to have private wells tested, according to The Hill. Details.
A new poll by the Value of Water Campaign released in late April shows that 84 percent of American voters want state and federal leaders to invest in water infrastructure. The near-unanimous support amid the COVID-19 pandemic reveals that voters value water and want elected officials to prioritize investing in infrastructure - specifically, drinking water and wastewater infrastructure. More. |
FAQ
This section always includes actual questions received since the previous Occasional and our actual answer.
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Question:
I just replaced the media in a 10 x 54 whole house filter with catalytic carbon and I am getting a lot of micro bubbles of air in the water that makes it look cloudy. Is this normal? Seems to be lasting a long time.
Answer:
Yes, this is normal. Sometimes it takes longer to clear the air than others. There is a lot of air trapped in new filter carbon.
See this article --
Question:
I was wondering if someone could tell me if any of the garden hose filters would work to take out sodium. My house has a complete water softener attached to it which unfortunately includes the outside faucets. It is a killer on plants. Would I be able to attach any of your filters to my outside house to water?
Answer:
I wish we had such a product, but we don't. Reverse osmosis is the only practical way to remove sodium and it isn't practical for situations like yours. For a few greenhouse plants, it works well, but not for extensive outdoor watering. Your best bet might be to have a plumber bring a spigot off of your pipe in front of the softener to use for outdoor watering.
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History of Hand Washing
Gazette’s Famous Water Pictures: Dr. Semmelweis Washing His Hands
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The idea “germs” that cause disease get on people’s hands and that they can be spread from person to person by unclean hands hasn’t been around that long. In fact, it was 19th-century Hungarian physician Ignaz Semmelweis who, after observational studies, first advanced the idea of “hand hygiene” in medical settings. Here’s how Semmelweis, working in an obstetrics ward in Vienna in the 19th century, made the connection between dirty hands and deadly infection.
Hand-Washing in the old days
While we certainly don’t know the name of the first guy to wash his hands, the history of hand-washing extends back to ancient times, when it was largely a religious practice. The Old Testament, the Talmud and the Quran all mention hand-washing in the context of ritual cleanliness, and it may be that ritual hand washing had some public health implications. During the Black Death of the 14th century, for instance, the Jews of Europe had a distinctly lower rate of death than others. Researchers believe that hand-washing prescribed by their religion probably served as protection during the epidemic.
Dr. Semmelweis
Hand-washing as a health care practice did not really surface until the mid-1800s, when a young Hungarian physician named Ignaz Semmelweis did an important observational study at Vienna General Hospital.
Semmelweis started working in obstetrics, a relatively new and not very prestigious area for physicians, in the Vienna Hospital in 1846. Obstetrics had up to that time been dominated by midwifery and conventional doctors were trying to expand into the childbirth business.
The leading cause of maternal mortality in Europe at that time was puerperal fever–an infection, now thought to be caused by the streptococcus bacterium, that killed postpartum women. Prior to 1823, about 1 in 100 women died in childbirth at the Vienna Hospital. But after a policy change mandated that medical students and obstetricians perform autopsies in addition to their other duties, the mortality rate for new mothers suddenly jumped to 7.5%.
When the hospital opened a second obstetrics division, staffed entirely by midwives, the older division, where Dr. Semmelweis worked, was quickly seen to have a much higher mortality rate than the new midwives’ division.
Semmelweis set out to investigate. He examined all the similarities and differences of the two divisions. The only significant difference was that male doctors and medical students worked in the first division and female midwives in the second.
What transmits disease?
At that time, the general belief was that bad odors called “miasma” transmitted disease. It would be two more decades at least before germ theory–the idea that microbes cause disease–took over as the accepted theory, the theory that persists until today.
Semmelweis reasoned that no midwives ever participated in autopsies or dissections, but students and physicians regularly went between autopsies and deliveries, rarely washing their hands in between. Realizing that chloride solution rid objects of their odors, Semmelweis ordered hand-washing across his department. Starting in May 1847, anyone entering the doctors’ obstetrical division had to wash his hands in a bowl of chloride solution. The incidence of puerperal fever and death dropped sharply by the end of the year.
Unfortunately, as in the case of his contemporary John Snow, who discovered that cholera was transmitted by polluted water and not miasma, Semmelweis’ work did not get him a place in history or even a promotion. In fact, he lost his job because his boss was envious of his success and got no recognition for the discovery during his lifetime.
Hand-washing has now, of course, become a part of the medical ritual, but it gets a definite bump of compliance whenever there is disease outbreak. Even in times of pandemic, though, we do not have a day on our calendar that honors Dr. Ignaz Semmelweis. There is no justice.
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Underwater explorers found a 150-foot-long (45 meters) siphonophore — a translucent, stringy creature that, like coral, is made up of smaller beings — living in a submarine canyon off the coast of Australia. It’s “seemingly the largest animal ever discovered,” they said.
Every individual siphonophore is made up of many little “zooids,” creatures that live lives that are similar to animals we’re familiar with, although they are always connected to the larger colony.
Zooids are born axsexually, and each one performs a function for the siphonophore’s larger body. Linked together in long chains, the colonies were already known to reach lengths of up to 130 feet, though each siphonophore is only about as thick as a broomstick.
The new, record-setting siphonophore was one of several discoveries made by a team aboard the research vessel Falkor while exploring deep-sea canyons near Australia’s Ningaloo Coast.
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Every glass of tap water has a host of cheerful microbes that promote your well-being.
When you drink a glass of tap water, you’re ingesting around 10 million bacteria found in water pipes and purification plants. But don’t worry – while it may seem utterly disgusting, the bacteria are actually good for you, according to a new study.
Researchers from Lund University in Sweden have discovered that bacteria and other microbes are found in the form of a thin, sticky coating in drinking water treatment plants and on the inside of water pipes.
Known as a ‘biofilm,’ the coating is inescapable because every surface involved in the process of getting drinking water to your tap is covered in it.
But according to the researchers, there’s absolutely no need to worry. In fact, you should be happy – because they suspect a large part of water purification happens inside the pipes, and not only in purification plants.
“We suspect there are ‘good’ bacteria that help purify the water and keep it safe – similar to what happens in our bodies. Our intestines are full of bacteria, and most of the time when we are healthy, they help us digest our food and fight illness,” researcher Catherine Paul said.
Although the biofilm is seen throughout the process, spotting it hasn’t always been easy.
“A previously completely unknown ecosystem has revealed itself to us. Formerly, you could hardly see any bacteria at all and now, thanks to techniques such as massive DNA sequencing and flow cytometry, we suddenly see 80,000 bacteria per milliliter in drinking water,” Paul said.
Paul and her colleagues noted that there is great variety among the bacteria and microbes, with at least a couple of thousand different species living in water pipes.
Although the research was conducted in southern Sweden, the researchers stressed that bacteria and biofilms are found all over the world in plumbing, taps and water pipes.
The scientists believe the study will be useful for countries when updating and improving their water pipe systems.
“The hope is that we eventually may be able to control the composition and quality of water in the water supply to steer the growth of ‘good’ bacteria that can help purify the water even more efficiently than today,” Paul said.
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Water Treatment 101: Scale
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Scale is a serious problem caused by the deposit of hardness minerals (mainly calcium and magnesium). Hardness can block piping systems, causing the loss of water pressure due to reduced pipe diameter, and it can greatly reduce the effectiveness of home heating systems and hot water heaters. Scaled pipes and appliances waste energy and money.
Scaling is caused by hardness of water. Hardness is defined, in simple terms, as the amount of calcium and magnesium present in the water. Hardness is measured either in parts per million or as grains per gallon. Water treatment professionals most often use grains per gallon. The conversion is easy: a “grain” is equal to about 17.1 parts per million.
Although there is no absolute standard, water is usually considered hard enough to cause problems at about 4 grains per gallon, and it is considered hard enough to require treatment at 7 grains per gallon and up. There is no upper limit on hardness, but water of 100 grains per gallon is rare.
The standard residential treatment for hard water is the conventional water softener, which exchanges sodium ions for the hard water minerals, calcium and magnesium. Conventional softeners are proven, reliable tools. They use salt in the softening process. In recent years a number of electronic and non-electronic softener substitutes have come on the market. Some of these are more effective than others. Template Assisted Crystallization (called TAC) is now the most widely used of the alternative scale preventives. TAC units not only prevent scale buildup but they remove existing scale as well.
Badly scalded water heater element after only 40 days service on 26 grains of hardness.
More information:
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The Viqua VH200 Series UV Units
The Perfect UV Unit for Most Residential Applications
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The Viqua VH200 F10
The compact but powerful Viqua VH200 ultraviolet unit is ideal for most residential use, either for well water or city water. Though it is rated for nine gallons per minute, the unit puts out double the dosage needed for bacteria like E. coli even at sixteen gallons per minute. This makes it plenty powerful for all but very large homes.
The VH200 is an economical unit that uses only about half as much current as a 60-watt light bulb and consequently it generates far less unwanted heat than more powerful UV units.
The VH200 comes from the factory in two formats: as a single, independent UV chamber, or as a bracket-mounted 2-stage system that includes a 4″ X 10″ sediment filter. (See picture above.) In either format it can easily be coupled with standard filtration equipment to add carbon filtration as well.
Viqua VH200 UV Unit comes complete with mounting bracket.
Easty to install, easy to maintain.
Here are some highlights:
- Versatile: Available with a sediment prefilter (Model VH200 F-10), and can be easily combined with other standard filtration equipment if desired.
- Convenient: Mounted on a reversible, heavy duty, painted steel bracket for installation flexibility and convenience. This means you can install with the inlet water on the left or on the right. Combo inlet fits both 3/4″ and 1″ pipe.
- Ease of Maintenance: Audible lamp replacement reminder and countdown timer with digital display. It reminds you when it’s time to change the lamp. Lamp life is a bit over a year. Controller will also go into alarm if the lamp fails.
- Reliable: The constant current feature ensures stable UV lamp output, regardless of power fluctuations
- Powerful: High-performance UV lamp, rigorously tested to provide consistent output over the entire lamp life (9000 hours). See power ratings below.
- Space Efficient: High UV output lamp technology allows for a smaller footprint, while maintaining the same UV dose as a longer chamber.
Features & Specs VH200 F-1
| Disinfection Flow Rates |
| 16mJ/cm2 |
16 GPM (60 lpm) (3.6 m3/hr) |
| 30mJ/cm2 |
9 GPM (34 lpm) (2.0 m3/hr) |
| 40mJ/cm2 |
7 GPM (26 lpm) (1.6 m3/hr) |
| Specifications |
| Dimensions |
17″ x 10 1/2″ x 18″ for VH200 F10. VH200 is 17.75″ X 3.5″. |
| Shipping Weight lbs (kg) |
26 lbs. for VH200 F10. (VH200 is 12 lbs.) |
| Connection Size |
1″MNPT INLET / 1″ x 3/4″ COMBO OUTLET. |
| Power Consumption |
35W |
Pure Water Products part numbers for these units are UV909 for VH200 single unit and UF918 for VH200 F-1 unit with sediment filter.
We also have upgrade kits that allow the VH200 to be combined with high flow carbon block systems.
Please call or email for information and pricing.
940 382 3814
pwp@purewaterproducts.com
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Covid-19 could infect the water supply, say researchers
By Engineering & Technology Editorial Staff
Published Monday, April 6, 2020
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Scientists are calling for more research into whether current water treatment methods are enough to kill Covid-19 to ensure it is not being spread through water infrastructure.
It is already known that coronaviruses, including Covid-19, can remain infectious for days or even longer in sewage and drinking water.
The virus is also commonly transported in microscopic water droplets, or aerosols, which enter the air through evaporation or spray.
“The ongoing Covid-19 pandemic highlights the urgent need for a careful evaluation of the fate and control of this contagious virus in the environment,” said University of California researcher Haizhou Liu. “Environmental engineers like us are well positioned to apply our expertise to address these needs with international collaborations to protect public health.”
During a 2003 Sars outbreak in Hong Kong, a sewage leak caused a cluster of cases through aerosolisation. Although this has not occurred during the current pandemic so far, its similarities to Sars mean this infection route could be possible.
It is also thought Covid-19 could colonise biofilms that line drinking water systems, making showerheads a possible source of aerosolised transmission. This transmission pathway is already thought to be a major source of exposure to the bacteria that causes Legionnaire’s disease.
Most water treatment routines are thought to kill or remove coronaviruses effectively in both drinking and wastewater. Oxidation with hypochlorous acid or peracetic acid, and inactivation by ultraviolet irradiation, as well as chlorine, are thought to be enough to eradicate the virus.
However, the researchers have cautioned that most of these methods have not been studied for effectiveness specifically on Covid-19 and other coronaviruses and are calling for additional research.
They also suggest upgrading existing water and wastewater treatment infrastructure in outbreak hot spots, which possibly receive coronavirus from places such as hospitals, community clinics and nursing homes.
Energy-efficient, light-emitting, diode-based, ultraviolet point-of-use systems could disinfect water before it enters the public treatment system. Potable water-reuse systems, which purify wastewater back into tap water, also need thorough investigation for coronavirus removal, and possibly new regulatory standards for disinfection, the researchers said.
“It is now clear to all that globalisation also introduces new health risks. Where water and sanitation systems are not adequate, the risk of finding novel viruses is very high,” said researcher Vincenzo Naddeo.
“In a responsible and ideal scenario, the governments of developed countries must support and finance water and sanitation systems in developing countries, in order to also protect the citizens of their own countries.”
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New articles on the Pure Water Gazette website:
Venturi Aeration Systems. An article from a long-ago Occasional made available for reference. We have parts and whole venturi systems (venturi valves, compact aeration tanks, passive vent valves), but they have to be ordered by phone. Part numbers are included in the article for reference when calling.
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Places to visit for additional information:
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Thanks for reading and be sure to check out the next Occasional!
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