Pure Water Occasional, August 27, 2019 |
Is your city water department hiding something in your neighborhood? If there's a home on your block with no sidewalk and no driveway, it may not be a residence but a . . . . Watch the video.
The endangered whale shark, reported to be the largest fish species on Earth, has been seen twice recently off the South Texas coast. The whale shark can weigh up to 11 tons and can reach a length of 40 feet.
Relationships among water constituents inside pipes are complex. We're learning that when manganese meets chlorine in a city water pipe, the result is often lead in the water. With the presence of manganese in city water on the rise, this is important. More information.
Turkey has started filling a huge hydroelectric dam on the Tigris river despite protests that it will displace thousands of people and risks creating water shortages downstream in Iraq. The Isisu Dam has been in the making for decades. More.
Starting next year, California water systems must notify residents if their water sources contain potentially toxic levels of cancer-linked chemicals called PFAS under a law Gov. Gavin Newsom signed in early August.
According to National Geographic, a comprehensive report done in 2013 found that humans kill 100 million sharks per year around the world, although another credible estimate puts the figure as high as 273 million. Why are so many sharks killed? "The culprit is the proliferation of illegal shark finning that spiked in the 1990s to feed appetites for shark fin soup, a delicacy in parts of Asia on par with fine truffles or expensive caviar. According to some reports, a bowl of shark fin soup can sell for as much as $100." In the practice of "finning," the shark's fins are cut off and the shark, unable to swim without fins, is returned to the ocean to sink to the bottom and die. Full article.
San Francisco has initiated an ambitious water recycling plan that is expected to save millions of gallons of water per year.
EPA Ignores "Shocking and Unambiguous" Evidence about Chlorpyrifos
The pesticide chlorpyrifos, a chemical cousin of nerve agents used in World War II, has been shown to impede brain development in children. But the Environmental Protection Agency under President Trump recently decided to reject an Obama-era plan to ban the pesticide.
In a July 25, 2019 op-ed in the Washington Post, Joseph Allen, assistant professor of exposure assessment science at Harvard T.H. Chan School of Public Health, wrote that chlorpyrifos has been associated with reduced IQ and working memory, delays in psychomotor development, and autism spectrum disorder in children. Allen called the science “shocking and unambiguous.”
The Trump administration went against decades of advice even from its own scientists in rejecting the chlorpyrifos ban, Allen wrote. In 2016, EPA scientists reported that there are unsafe levels of chlorpyrifos on food crops and in drinking water. (Source: Harvard University.)
People Having Sex in Bathrooms to Be Punished with Water
The Welsh seaside town of Porthcawl is planning to install anti-sex public toilets that would spray occupants with water and sound an alarm. Violent movement sensors would automatically open the doors and sound high-pitched alarms, with fine water jets soaking the interior. Weight-sensitive floors would ensure only one user could be in a cubicle at a time, to safeguard against “inappropriate sexual activity and vandalism."
Porthcawl town council is spending £170,000 on the futuristic toilets. Cynical critics of the plan have pointed out that the use of weight-sensitive flooring might lead to the dousing of single large but innocent bathroom users or, heaven forbid, allowing two very light sexual misbehavers to go un-squirted. Did we make this up? No, it's from the Guardian.
Alaska has been in the throes of an unprecedented heat wave this summer, and the heat stress is killing salmon in large numbers. Scientists have observed die-offs of several varieties of Alaskan salmon, including sockeye, chum and pink salmon. Salmon are dying because water temperatures are too high. Details.
A significant new study of mothers who drink fluoridated water during pregnancy indicates that "Fluoride exposure during pregnancy may be associated with adverse effects on child intellectual development, indicating the possible need to reduce fluoride intake during pregnancy." More specifically, "Fluoride exposure during pregnancy was associated with lower IQ scores in children aged 3 to 4 years." The full study is in Medical News Today.
You may have noticed that water polo is evolving rapidly into a very popular sport—so popular that wealthy parents buy fake water polo credentials to get their sons and daughters into the finest universities. 2019 marked the 50th anniversary of the USA Water Polo National Junior Olympics. In its half century lifespan, the tournament has evolved from a regional novelty to a national behemoth. Over two weekends last month, almost 900 boys’ and girls’ teams played hundreds of games in Southern California.
Scientists testing rainwater around metro Denver and high in the Front Range mountains found microscopic bits of colored plastic in more than 90% of their samples — adding to growing evidence that plastics have contaminated the planet far more deeply than people can see. Read the full article in the Pure Water Gazette.
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Acidic Water
by Pure Water Annie
Gazette technical wizard Pure Water Annie offers a nutshell view of treating acid water.
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Acidic water is, by definition, any water with a pH of less than 7.0.
Water that is low in pH can have undesirable effects on plumbing fixtures and piping. Green staining of fixtures is a common indication of acidic water. Copper pipe can be ruined by water low in pH.
Low pH is also an issue in water treatment. Sometimes it is necessary to raise the pH of acidic water in order for other treatment strategies to apply. For example, oxidizing iron to prepare it for filtration is difficult if the pH of the water is low, so raising the pH of the water is often the first step in removing iron from well water.
Almost all water treatment issues involve pH in some way. Water constituents change in nature as pH changes, so many treatments can be applied only if pH is within the desired range.
Although the sales strategy of a class of drinking water products called “ionizers” is based on raising the pH of acidic water, there is no evidence that drinking water low in pH has any negative effect on health. Taste, of course, can be an issue if the pH is very low.
Treating Acidic Water
The pH value of water decreases as the amount of carbon dioxide, CO2, increases, and pH increases as the amount of bicarbonate alkalinity increases. The ratio of carbon dioxide and bicarbonate alkalinity within the ranges of 3.6 to 8.4 is an indication of the pH value of the water.
Acidic water can be corrected by several water treatment strategies. A common treatment is injection of soda ash, and a more aggressive treatment is the injection of caustic soda (sodium hydroxide). This is usually accomplished by injecting a solution of the soda ash or caustic soda directly into the water pipe.
A second strategy is to run the water through a bed of calcite (the most common treatment mineral) or corosex. As the low pH water passes through the bed, the mineral dissolves into the water and raises its pH.
Calcite treatment raises the pH by adding calcium carbonate to the water. This has the sometimes undesirable effect of increasing the hardness of the water slightly. Calcite and corosex are most commonly used in backwashing filters, but calcite alone can be used with simple upflow filters if the water is reasonably clean. Calcite is also commonly used in cartridge form as a postfiltration treatment for undersink reverse osmosis units. RO lowers pH, and calcite filters are used to bring the pH back to neutral.
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The Current Status of US and UK Regulation of PFAS.
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(Excerpted from a Harvard School of Public Health article by Dr. Phillipe Grandjean.)
Q: Are governments in Europe and the U.S. taking any action to regulate PFASs?
A: The Council of EU Ministers recently concluded that the European Commission should generate a joint EU strategy on PFASs, treating all the many individual compounds as a group and recommending that they be approved only for essential uses. This means that two commonly used PFASs, such as PFOA and PFOS [perfluorooctane sulfonic acid], cannot be swapped out for other PFASs, except for uses considered “essential.” This is being done because the entire class of chemicals is suspected of having similar properties in regard to environmental dissemination and human health.
Individual EU agencies are currently working on more specific issues, such as lowering tolerable limits in drinking water and phasing out the use of PFASs in food wrappings.
In the U.S., older PFASs are being phased out but they are being substituted with similar PFASs that have not yet been tested in any detail and are therefore not regulated.
There are some legislative efforts underway in Congress to address the use of PFASs, and these are of course highly beneficial and appropriate. For example, one proposal would require a number of actions, including the stipulation that the EPA set nationwide drinking water regulations for PFOA and PFOS. But the proposal would give the EPA two more years to address what are termed “unreasonable risks” from these chemicals, which is generous, as EPA has been aware of the growing problems for a very long time. It’s also not clear if President Trump will approve these congressional proposals. He recently threatened to veto a bill that would phase out the military’s use of firefighting foams that contain PFASs and that has led to the contamination of vast groundwater reservoirs.
States continue to be impatient and have developed their own approaches to control what some call the PFAS “crisis.” Most recently, New Hampshire has announced new water limits for the four major PFASs, with limits for two of those, PFOS and PFOA, about five-fold lower than the EPA guidelines. At least six other states have also set limits below EPA guidelines.
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RO: Large and Small
Over the years we've been consistent and enthusiastic reverse osmosis boosters. Without challenge, RO is the best all-around home treatment for most drinking water contaminants. RO covers it all—including the persistent issues like lead, PFAS, fluoride, arsenic and nitrates. An undersink RO unit is the best investment for years of superior quality drinking water. We're very proud of our basic undersink Black and White RO units. We've been making Black and White for over 25 years now and we get better at it all the time.
The three articles below feature other RO offerings. The "countertop" RO, which is part of the Black and White series, was designed mainly as an inexpensive source of superb drinking water for anyone who doesn't want to do a permanent undersink installation. We've found, however, that it has so many other uses that we've started calling it a utility RO unit. The articles below will explain.
Big residential RO units are featured in the final article. We've sold Watts R12 series units (600 and 1200 gallons-per-day) for a number of years, and have recently added Watts R4X40 series units that produce 2200, 4400, and 6600 gallons per day. The article below discusses their application.
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Countertop Reverse Osmosis Doesn’t Have to Sit on the Countertop
by Gene Franks
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The countertop reverse osmosis unit pictured above produces top quality reverse osmosis water at the rate of a couple of gallons per hour. The water quality is equivalent to that produced by an undersink RO unit costing double the price. It is an extremely versatile machine that can be used for many purposes.
The countertop RO unit is most commonly used as a bottled water maker, installed to the sink faucet and allowed to produce water into a bottle. When the bottle is filled, you turn the unit off. You can then leave it in place or remove it. The drain water (all reverse osmosis puts out a trickle of reject water) exits via a separate hose that is simply dropped into the sink.
The usual way to get water to the unit is with the standard diverter valve, like the one below, hooked to the kitchen faucet. You pull out the knob to divert water into the RO unit. The knob stays out until you turn off the water.
Standard Diverter Valve
However, there are many other uses and methods of installation. For example, the RO unit can be attached directly to a water line in a laundry room or patio–anywhere there’s a water source and a place to send the drain water. With a simple adapter it can take its water from a garden hose or outdoor faucet for use on a patio or greenhouse.
With modern day sink faucets, especially those with pull-out sprayers, it is often impossible the use the diverter valve. In this case the RO unit can be fed from an undersink water source identical to the inlet line used for undersink filters and RO units. In these installations, the feed line is pulled from under the sink and attached to the RO unit with a push-in fitting. After water has been produced, the RO unit is removed and the feed line is conveniently stored under the sink. See the picture below.
A simple adapter like the one in the picture can be used to provide water from a kitchen or laundry room undersink to a countertop reverse osmosis unit. The blue-handled valve can be located at a more convenient place nearer the delivery end of the tube if desired. When not in use, the tube can be removed from the RO unit and stored under the sink.
Here are some more ideas for countertop RO units.
Aquarium filler. Water is collected in a large container for subsequent addition to the aquarium. The RO unit can be turned off and on manually, or a simple automatic shutoff system can be added to the RO unit that turns it off when the container is full. The shutoff system is inexpensive and easy to add to an existing countertop RO unit.
Outdoor pond filler. The unit can be allowed to fill the pond when it is turned on manually or it can be installed to top off the pond and shut off automatically with a float valve when the pond is full. A garden hose adapter (see below) will allow the user to produce RO water from a garden hose.
Final rinse water for a spot-free car wash. The water for car washing is usually captured in a small tank, then pumped to provide pressure for the car wash. A deionizing cartridge can be added to provide zero-TDS water if desired. The standard countertop RO unit can make up to 50 gallons of RO water per day (and it can be easily modified to produce more). The pump setup is easy to make from standard water treatment parts.
High quality water for plants, either in small outdoor gardens or greenhouses. This application also requires capturing then pumping the water to the point of use, although small drip systems can be designed that take water directly from the RO unit. For small operations, the water can be produced into a small tank and then dipped out with a bucket or pitcher to water plants.
High quality water for dehumidifiers or other appliances that require water that does not leave mineral deposits. Again, it is easy to modify the RO unit so that it feeds water to the appliance upon demand.
This handy fitting screws onto the end of a garden hose or outdoor faucet to make an easy connection to a countertop RO unit. It is provided free for the asking when a Black and White countertop RO unit is purchased.
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Car Wash Reverse Osmosis: Build Your Own Simple System
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Car wash products have never been our favorites.
We believe that the best place to wash a car isn’t at home but in a professional car wash establishment. Commercial car wash locations are set up to furnish water for spot free rinses at a reasonable cost, to recycle water, and to get rid of the wastewater in a much more environmentally friendly way than you can at your home. At home, the soap, chemicals, and wastewater end up in the worst place you could put them–in the storm drain.
Nevertheless, home car washing is extremely popular, and there are probably worse things people could do with their time than washing their cars.
We sell a garden hose filter with a softening cartridge that has been very popular. It isn’t perfect, but if you use it according to instructions it will do a fair job of knocking down the hardness minerals (calcium and magnesium) that cause spots on cars. This helps in many cases but in others not so much, because the softening process (whether it’s done by our tiny cartridge or by a full-fledged home water softener) doesn’t always solve the problem. Softening removes the hardness (calcium and magnesium) from the water, but it adds an equal amount of sodium, which also can cause spotting. So, washing with softened water helps, but you often still have to wipe away the spots caused by the sodium.
The only way to get a real spot free wash is with low mineral water and the only practical ways to produce this are with deionization (DI) or reverse osmosis (RO), or with a combination of the two.
Softening “exchanges” ions–salt for calcium and magnesium–but DI removes all of the minerals. DI makes water that’s perfect for a spot-free car wash, but it has the drawback of being very expensive. Softener resin can be regenerated at home, but DI resin can’t, and it doesn’t last long.
The small garden hose car wash “filters” that come and go (Mr. Clean, for example) are DI units. They work well, but cost is so high that it would almost make more sense to trade in your car for a new one when it gets dirty. There are lots of larger refillable DI home car wash units on the internet now that allow you to buy resin in bulk to cut the cost. Buying in bulk is better than buying small individual cartridges, but any way you do it, DI costs a lot and continually changing the resin is no fun.
Reverse Osmosis removes about 95% of the minerals in water–both hardness minerals and sodium–not by exchanging but by straining them out. RO is what car wash establishments use to get “spot free” water, and it is the most economical way to do it at home.
RO is a slow process, so a storage tank is needed. In the simple home RO car wash setup shown above, the small RO unit might need half a day or more to put enough water into the storage tank to wash a car. (But, what’s time to an RO unit?) The low-mineral RO water is then sprayed onto the car using the small “demand” pump. If only the final rinse is done with RO water, a small tankful of water is plenty.
Although there is an initial investment, RO is the most economical source of spot-free rinse water. The simple unit shown above, without the tank (any plastic tank, including a strong garbage can) will work costs only about $350 for the essential parts–the RO unit and the pump. Upkeep is small.
This simple system can be enhanced with items like a float shutoff to make filling automatic, larger tanks and larger pumps. The small “countertop” RO unit will make as much water as you want if you give it the time.
This simple system, of course, does not have to be used for car washing. It works well for small greenhouses, aquariums, and more–any venue in which a small amount of top quality water is needed.
RO water is a lot like rainwater, so having the system shown above is like having a rain barrel but not having to wait for it to rain.
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Whole House Reverse Osmosis for Residential Wells
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The most common reason for buying a whole house reverse osmosis unit for a residential well is to treat water with such high salt content that it is otherwise essentially unusable. RO is the only practical way for residential users to remove large amounts of minerals like sodium and chloride from well water.
For most other problem contaminants with wells, like hardness, iron, and manganese, there are easier ways than reverse osmosis, and some contaminants, like arsenic and nitrates, which are removed well by RO, are most often addressed as drinking water but not whole house treatment problems.
Before and After Test Results for a Whole House RO Unit
Below is a chart showing before treatment and after treatment results from National Test Labs tests made by one of our customers. The high TDS (Total Dissolved Solids) water is treated with a sediment filter, a water softener (to protect the reverse osmosis unit), then with a Watts R12 1200 GPD RO unit. This water is typical of what whole house residential reverse osmosis is used for–bringing the TDS count down to a level where the water is usable for household purposes.
I’ve selected a few items from the tests that illustrate typical RO performance on high TDS well water.
| Contaminant or Characteristic |
Untreated |
Treated |
% Reduction |
| Lithium |
0.352 ppm |
0.007 ppm |
98% |
| Silica |
12.5 ppm |
0.7 ppm |
94% |
| Sodium |
761 ppm |
15 ppm |
98% |
| Hardness |
260 ppm |
0 ppm |
100% |
| pH |
7.6 |
5.7 |
NA (See comment below.) |
| TDS |
2400 ppm |
84 ppm |
97% |
| Chloride |
310 ppm |
17 ppm |
95% |
| Fluoride |
3.6 ppm |
0 ppm |
100% |
| Nitrate |
2.2 ppm |
0.6 ppm |
72% |
| Sulfate |
960 ppm |
0 ppm |
100% |
A whole house reverse osmosis system consists of a lot more than the reverse osmosis unit itself. In most cases the water will need pretreatent for sediment, hardness, iron, and manganese to protect the RO membrane(s).
Most large RO units produce water into a non-pressurized tank, so a pump will be needed to send the water to the home. RO lowers the pH of the water (see test results above), so a neutralizing filter is usually added after the RO unit to to protect the home’s pipes and appliances from acidic water. An ultraviolet unit is usually added as the final stage to assure that the water is microbiologically safe.
You can normally expect the cost of pre-treatment, storage, delivery to the home, and post-treatment to be as much as the cost of the RO unit itself.
Whole house RO units are not trouble free. They require some attention, especially if pre-treatment equipment is used. One issue that people often overlook is that a lot of wastewater is generated and this has to be disposed of. Expect at least half the water that goes into the unit to come out as reject water, or brine, so if your family uses 300 gallons of water per day, you will have at least 300 gallons of reject water to get rid of.
Disposal in rural environments can often be arranged so that septic systems are not overwhelmed. The homeowner who sent us his test results catches the RO brine in large holding tanks and blends it with rainwater to produce water suitable for irrigation.
Above is a 2200 gallon per day Watts R4X40 reverse osmosis unit. We offer Watts units that produce 600, 1200, 2200, 4400, and 6600 gallons per day. The unit shown includes low pressure cutoff to protect the unit if inlet pressure falls too low, pump to send pressurized water to the membrane, flow meters to measure both the permeate (product water) and brine (reject water) as they leave the membrane, a TDS meter to give instant TDS readings for both the untreated water and the permeate, and a manual control to allow part of the brine to be recycled for treatment.
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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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