Pure Water Occasional, March, 2023
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Greetings from Pure Water Products, the Pure Water Gazette, and the Pure Water Occasional.
In this almost-Easter Occasional you'll hear a lot about PFAS, turbidity and bold suggestions for solving the water shortage in western states. Read about the old faithful Fleck 5600 control valve, the mighty Sand Trap, sediment filters, PFAS in toilet paper, nonstick pans, water-repellent fabrics, fire-fighting foam, and military bases. Hear about bold plans to save water by cutting down forests and using nuclear power to treat 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 website, where there is much information about water treatment and the products we offer. On both sites pop-up ads and other distractions are stricly against the law.
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Turbidity
Turbidity is technically a measurement of the degree to which particulate in the water interferes with light transmission. Suspended particles absorb and diffuse light. Testing water for turbidity measures the diffusion of light as it passes through the water.
High turbidity can be identified without a water test.
A turbidity test uses an instrument that passes light through the water and measures the amount of interference from suspended particles.The turbidity test reports results on an artificial scale using nephelometric units, or ntu. Anything above one ntu is technically an EPA “action level” violation, although the human eye only begins to detect turbidity in water at about 4 ntu. Therefore, water that appears completely clear to the eye can have excessive turbidity with health implications.
Turbidity in groundwater is often from tiny mineral particles. These can include precipitated iron, clay particles or calcium carbonate precipitation. In surface water turbidity is more likely suspended organic matter or other sediment.
The level of turbidity can, of course, range from invisible to the eye to highly colored water that is not transparent.
Turbidity in water is more than an aesthetic issue. It is a frequent indicactor of microbial contamination because microbes can attach themselves to suspended sediment. Turbidity also makes it more difficult to disinfect water with chemicals. The same is true with UV treatment because suspended particles can shadow microbial contaminants protecting them for the germicidal effect of the UV lamp.
Residential sediment treatment can range from the "Sand Trap," shown above, which relies on gravity to drop large particles from the water, to extremely tight membrane filters that can screen out sub-micron sized particles.
Treatment for turbidity is mainly by filtration. Sediment filters can be cartridge style, granular beds, or membrane-style. With large particles, simply holding the water in a tank will allow particulate to settle out. In municipal treatment, settling and filtration are often aided by chemicals like alum which promote coagulation and flocculation of small particles to form larger particles that settle out or are filtered easily. The very tiniest of particles can be treated by extra tight filter technologies called microfiltration and ultrafiltration and even tighter membrane systems like nanofiltration and reverse osmosis. Reverse osmosis can remove particles down to 0.001 microns.
It is important to realize that turbidity in water is not just an aesthetic consideration. While crystal clear water is certainly more appealing to the eye and to the palate, turbidity is also an important health consideration because microbes thrive in unclean water. Even if water appears clear, it is a good idea to test for turbidity and to take high turbidity readings seriously.
Not all cloudiness in water is particulate. When cloudy water clears from the bottom upward as in the picture, the problem is not physical particulate but simply excess air trapped in the water. This sometimes occurs when carbon filters are new or when aerating treatment products are being used.
Commonly used sediment filters:
Simple wound string, spun polypropylene and pleated cartridge filters are available in a large range of “tightness” ratings that are stated in “microns.” Cartridge filters range in size from tiny to very large. Probably the most common residential whole house sediment filter is the popular ten-inch “Big Blue.” With cartridge filters, the smaller the micron size, the tighter the filter. The smaller the number, the more effective the filter, but also the easier it is to clog and the more it resists flow and drops water pressure.
“Spin down” separators that are usually measured by “mesh” size. These have long lasting screens that are cleaned by simple blow down process. With mesh sizes, the larger the number, the tighter the filter. A 60 mesh screen is looser than a 100 mesh screen.
“Sand traps” that allow large particles to drop from the water into a specially designed filter tank.
Backwashing filters that contain specialty media designed to trap sediment. The newer natural zeolite media can filter down to 3 microns.
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Only Fleck 5600 on Our Website Now
By far our most popular backwashing filters over the years have been those built with the reliable and very user friendly Fleck 5600 control. Now only 5600 filters are shown on our website. We made the change to 5600 only for water softeners a couple of years ago and it has worked out well.
The 5600 has size limitations. It works only on filters that need a backwash rate of 7 gallons per minute or less. If a larger filter than those shown on our site is needed, we can supply it, but it can’t be ordered from the shopping cart. We still stock and support the Fleck 2510 models that were recently taken down, but they are available by phone only so that we can assure that they are properly sized. We also sell much larger filters and softeners with Fleck 2815 and 3150 and Nelsen C-Series (Clack) controls that are not shown on the website.
The very popular Fleck 5600 SXT (simple electronics) control, pictured above, is ideal for customer-maintained filters. No special tools are needed for repairs and parts are easy to find. We program the control before it is shipped, and changes in programming are easy. We still supply the time-clock version of the 5600 as well for those who prefer it.
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New PFAS guidelines – a water quality scientist explains technology and investment needed to get forever chemicals out of US drinking water
Chemicals used to create water-repellent fabrics and nonstick pans often contain PFAS and leak those chemicals into the environment
Harmful chemicals known as PFAS can be found in everything from children’s clothes to soil to drinking water, and regulating these chemicals has been a goal of public and environmental health researchers for years. On March 14, 2023, the U.S. Environmental Protection Agency proposed what would be the first set of federal guidelines regulating levels of PFAS in drinking water. The guidelines will be open to public comment for 60 days before being finalized.
Comments that follow are from Joe Charbonnet, an environmental engineer at Iowa State University who develops techniques to remove contaminants like PFAS from water. He explains what the proposed guidelines would require, how water utilities could meet these requirements and how much it might cost to get these so-called forever chemicals out of U.S. drinking water.
1. What do the new guidelines say?
PFAS are associated with a variety of health issues and have been a focus of environmental and public health researchers. There are thousands of members of this class of chemicals, and this proposed regulation would set the allowable limits in drinking water for six of them.
Two of the six chemicals – PFOA and PFOS – are no longer produced in large quantities, but they remain common in the environment because they were so widely used and break down extremely slowly. The new guidelines would allow for no more than four parts per trillion of PFOA or PFOS in drinking water.
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Water News Briefs for March 2023 (Warning: It ain't good.)
New studies reveal that toilet paper can be a serious contributor to PFAS levels found in wastewater. Phys.org. For information about the origin of PFAS in toilet paper and its significance, see the excellent Guardian report.
Lake Mead continues to shrink and is now at the lowest level it has been since it was first filled. “Lake Powell, the nation’s second-largest reservoir and one that provides water and power to millions of people in southern California, has reached its lowest levels since its first filling in the 1960s,” USA Today reported. “If the lake’s level falls much lower, it won’t be possible to get water out of it. If the lake falls another 32 feet — about the amount it fell in the past year — power generation concerns become more urgent.” Pure Water Gazette. Ironically, as many areas suffer with record drought, recent storms have filled some California lakes to their highest level in years. Newsweek.
Alarmingly high levels of PFAS have been found in lakes in Alaska's two largest cities, Fairbanks and Anchorage. Some lake water has PFAS levels 1000 times what is considered safe for drinking water. "Use of PFAS compounds began in the 1950s, and there are thousands of them. Most famously, they are found in flame-suppressants. Most of the environmental PFAS contamination in Alaska and many other places is believed to have been caused by use of those firefighting foams at airports, where their use is mandated by the Federal Aviation Administration. Military sites are also known for using such foams. But the PFAS compounds are widespread in consumer and industrial products like nonstick cookware, clothing, upholstery and personal-care goods such as shampoos. They are called “forever chemicals” because they do not degrade." Alaska Beacon.
An estimated 8,100 gallons of latex finishing material, a water-soluble acrylic polymer solution, was released into Otter Creek in Bristol, Pennsylvania, on March 25. This is one of many chemical spills recorded this month. Boil water alerts are expected. Yahoo.
The EPA has determined that US military bases with cancer-linked PFAS-contaminated drinking water have been significantly undercounted. "Data obtained from the Department of Defense (DOD) by the Environmental Working Group (EWG), under the Freedom of Information Act, show that locations with notably high levels of total PFAS include Fort Leavenworth, in Kansas; the Joint Forces Training Base, in California; Belmont Armory, in Michigan; McChord Air Force Base, in Washington; Fort Hunter Liggett, in California; and the Sierra Army Depot, in California." When water at military bases is contaminated, communities in their vicinity are usually at risk as well. Water Online.
The EPA has released new draft Maximum Containment Levels (MCL) for PFOA and PFOS (collectively part of the group of chemicals known as PFAS) permissible in drinking water at a national level. The new allowable levels are 4 ppt for PFOA and 4 ppt for PFOS. For context, one part per trillion is one drop per 21 million gallons of water. See the full article below from Environmental Health News for details.
Chinese archaeologists discovered what may be one of the world’s oldest manual flush toilets — dating back 2,200 to 2,400 years, per Live Science.
A massive 5,000-mile seaweed bloom is approaching the Florida coast and threatening water quality. The seaweed, known as sargassum, can tangle up boats and other marine machinery, release dangerous hydrogen sulfide, and inundate beaches. The seeweed is laced with heavy metals like arsenic which make disposal and reuse extremely difficult. Research suggests the causes for this massive bloom are related to climate change and are similar to those that have been driving increases in source water algal bloom, which threatens drinking water quality, across the country. Water Online.
Are We Slowly Dying of Thirst?
The world is facing an imminent water crisis, with demand expected to outstrip the supply of fresh water by 40% by the end of this decade, experts have said on the eve of a crucial UN water summit. Governments must urgently stop subsidising the extraction and overuse of water through misdirected agricultural subsidies, and industries from mining to manufacturing must be made to overhaul their wasteful practices, according to a landmark report on the economics of water. Nations must start to manage water as a “global commons,” because most countries are highly dependent on their neighbors for water supplies, and overuse, pollution and the climate crisis threaten water supplies globally, the report’s authors say. -- The Guardian. Likewise, the U.N. issued a warning that "vampiric overconsumption" is rapidly depleting the world's water supply. BC Water News.
Plasticosis
The world’s oceans are permeated with plastic waste, from surface waters to some of their deepest reaches. And we know from numerous studies that fish, turtles, seabirds and smaller sea creatures are ingesting bits of plastic when they feed. Now, scientists are starting to pin down the effects of a plastic diet.
Marine scientist Matthew Savoca explains findings from a recent study that identified a new illness, which the authors call plasticosis, in seabirds. Scarring in the birds’ digestive tracts resembles effects in humans who are longtime smokers or have been exposed to asbestos. As Savoca sees it, plasticosis “could be a sign that a new age of disease is upon us because of human overuse of plastics and other long-lasting contaminants, and their leakage into the environment.” The Conversation.
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