Pure Water Occasional, September 7, 2017
In this late summer Occasional you'll read about E. coli in New Zealand, flooding in Texas and Louisiana, diversion tunnels in California, drainage tunnels (or lack thereof) in Houston, the politics of water infrastructure, the politics of water softeners, and a new Chromium rule for California. Learn where Poland Springs water doesn't come from, how much water is in a potato, how much air is in a carbon filter, how many tons of old Occasionals you can find in our new archive, and, as always, there is much, much more.
NEW ARCHIVE FOR OLD NEWSLETTERS
We've established a new archiving system for old Pure Water Occasional issues. Email issues going back to mid-2006 now link from the Pure Water Gazette site.
They're listed chronologically but you'll have to click to find what's in them. We haven't counted them, but there are a bunch. Here's where they are:
The Occasional is the offspring of the original Pure Water Gazette which began as a mail-out paper newsletter in 1986. The paper Gazette issues were discontinued in 1997 and morphed into an online-only publication which started emailing as the Occasional sometime in the early 2000s.
It has existed since then as an online publication with "occasional" email issues. There is also a list of partially indexed back Occasionals archived on the Pure Water Occasional website. These cover roughly 2009 to 2013.
The Great Variety of Carbon Filters
We just counted.
In the “Cartridge Menu” at purewaterproducts.com there are more than fifty separate carbon filter cartridges, and that’s just in the four standard sizes. These range from carbon blocks to granular carbons, many with specialty additives like calcite and KDF. There are coconut shell carbons, bituminous carbons, and lignite carbons. Additionally, there are carbon filters enhanced to remove lead and cysts, to prevent scale buildup, to inhibit bacterial growth, to remove fluoride, to reduce tannins, and to raise pH. There are carbon filters that target VOCs and others that offer fantastically long and effective chlorine reduction.
In addition, there are “proprietary” carbon filters for a number of brands (Microline, Hydrotech, for example), inline carbons (from Pentair and Omnipure), aftermarket knock-offs (Multipure), and several ceramic candles with carbon cores.
Filter carbon is the central core of most modern water filtration systems. For some 90% of the water contaminants monitored by the EPA, carbon filtration is the preferred treatment. We hope you’ll look over our carbon collection. Our “Cartridge Menu” offers extensive information on all the carbon filters that we sell, including pictures, performance summaries, and links to manufacturers’ brochures.
Air and Water Filter Carbon
by Gene Franks
A little understood fact about granular carbon - any carbon used in filters, as a matter of fact - is that it contains a lot of air. What appears to be a pile of dry granules is actually the hiding place for countless tiny pockets of air. According to an article in Water Quality Products Magazine: "In a typical bed of dry activated carbon, the carbon skeleton only occupies 20 percent of the bed. The remainder is air."
About half the trapped air is in the voids between the granules of the carbon. The other half is in the pores of the granules. Carbon granules are shot full of acres of many tiny crevices. These nooks and crannies are the very thing that gives carbon so much surface area and makes it such an effective adsorbent. A carbon particle only around 0.1 mm wide has a surface area of several square meters. In more dramatic terms, an EPA document states that GAC has an adsportion surface area from around 73 to 112 acres per pound!
Owners of even small carbon filters know that when water encounters carbon for the first time a lot of hissing and sputtering occurs. This is the sound of trapped air that is escaping from within the carbon.
In small filters, when water enters the new filter bed for the first time, the air that is displaced works itself out naturally in time. Othen than giving the new carbon a thorough rinse, nothing needs to be done to speed the process up. Air can be recognized in the product water of new carbon filters by the cloudiness it produces. Draw a glass of water from a new carbon filter. If the water is cloudy, watch it clear. If the cause of the cloudiness is air, the milky color will clear from the bottom upward. Often, after the water clears, what appears to be scum will be left on the top surface of the water. This is air trapped by the water's "skin" or surface tension at the top of the glass. It's of no concern.
In larger carbon beds used in tank-style filters it is often advantageous to allow a long soak - from overnight to several days, depending on the bed size and water temperature. This is because large air pockets can make the filter perform poorly. The filter, in fact, will not perform normally until all the air is gone. In some very large systems technicians resort to introducing heated water to speed the process up. This isn't recommended for homeowners. In small filters, trapped air is often just an aesthetic inconvenience, but it can sometimes cause "vapor locks" in undersink filters and reverse osmosis units. This condition can be relieved by simply opening a filter canister to allow the trapped air to escape. In RO units, most prefilter air escapes through the drain line of themembrane housing (that's the hissing you hear when you start a new or a newly-serviced unit), and most postfilter air is expelled through the faucet. Rinsing the unit well usually gets rid of excess air quickly.
A vigorous backwash of up to 30 or 40 minutes can serve three purposes in new backwashing filters:
It rids the carbon of fines (carbon dust), it resettles the bed so that smaller granules work their way to the top, and it clears out air pockets.
The best policy for starting non-backwashing In/Out-type filters is probably a very long soak before the unit goes into service. It could take up to 48 hours to get all the air out at ambient temperature, but the longer soak you can give the carbon before putting the filter in service the less air you’ll get into your home’s water pipes. Always open a downstream faucet to allow air to escape.
FYI: in industrial applications, air-release time can be cut to 3 to 4 hours by using 212 degree F. water. At 1800 degrees, air expulsion is instantaneous.
Enlargement of granular carbon shows countless pores that adsorb contaminants. The surface area of the pores is exceptional. A single pound of activated carbon has more surface area in its pores than 100 football fields. When the carbon is new, these pores are filled with air that must eventually work its way out.
The Politics of Water Softeners
by Gene Franks
To combat salinity in waste water systems and to save water, cities are adopting regulations that range from outright bans on conventional softeners to laws rewarding customers for obtaining high efficiency units or getting rid of their softener altogether.
The following is from the Water Quality Association’s newsletter (May 21, 2014):
Water Softeners Remain a Prominent Issue in Arizona
The Water Quality Association and Arizona Water Quality Association continue to monitor several issues in Arizona, where water softeners are very much the topic of legislative and regulatory focus.
Arizona’s Legislative Salinity Committee issued its report to the legislature, making several recommendations, including an education outreach program for both water treatment installers and the general public about the effects of salinity in the Valley of the Sun. It also recommended the State adopt the California Water Softener Performance Standard: that a water softener must remove at least 4,000 grains of hardness per pound of salt used and a maximum of five gallons of water per 1,000 grains of hardness removed. HB 2117, which included the language for water softener performance standard, was introduced in the Arizona House of Representatives earlier this year. Despite passing in the House, the bill failed to be taken up by the Arizona Senate.
In March, the City of Scottsdale approved a two-year pilot program to begin using rebates to encourage consumers to change their water softening practices. These are not cash rebates, but would be credited to the applicant’s water bill. Scottsdale is offering three different rebates, including:
- A $50 one-time rebate available to the first 300 customers each year who replace their existing water softener with a new high-efficiency device.
- A $100 one-time rebate available to the first 100 customers per year who subscribe to a portable exchange service.
- A $250 total rebate ($125 up front $125 after one year) to the first 100 customers who remove their water softener completely.
Exactly how the city would enforce the “4,000 grains of hardness per pound of salt” rule isn’t explained and is hard to imagine. Perhaps the measure can be implemented by adding more code enforcement officers with flow meters, test kits, and scales for weighing salt. But the point that bothers me is paying someone to remove his softener altogether. Does the softener have to be working, or can the homeowner just get rid of an old softener that’s stored in his garage? It reminds me of a plan that our city had to give special price breaks to people who turned off their air conditioners at peak usage times. I complained (bitterly) that there was no provision in the law to reward me for not having an air conditioner to turn off. Once our city government gave awards to people who stopped bagging their grass clippings. There was no award for me who has never in my life bagged a single blade of grass. Nor have I ever been given an award for not watering my lawn or for not mowing it, though these save water and energy and reduce pollution.
The dilemma that city officials face with the air conditioner and the water softener is they want you to save water, but not too much water; they also want you to save electricity, but not too much electricity. City utilities companies, after all, get paid by selling water and electricity and if too many people save too much there’s a budget shortfall. So, we are trained that to be good Americans we should water our lawns, but not too much, and that we should have an air conditioner, but turn it off at times when we need it most.
The world is not simple.
Reverse Osmosis and Refrigerators
by Gene Franks
The permeate pump runs on water pressure from the RO drain line and needs no electricity. In addition to sending higher pressure to the refrigerator, it improves the RO unit's efficiency so that it uses less water.
As refrigerators get more complex and offer features such as cold water dispensers, it is becoming more common to feed them with high quality water from an undersink reverse osmosis (RO) unit. The challenge in such hook-ups is how to provide sufficient water pressure for the refrigerator, especially since many of the newer refrigerators and ice machines require more feedwater pressure than older models.
With simple filters, just teeing into the undersink filter’s faucet tube works fine, since filters put out essentially the same pressure as the tap water source. With RO units, however, a standard system puts out only about 2/3 of the tap water pressure when the RO storage tank is full, and, of course, less as water is taken from the storage tank.
If city water pressure is strong–say, 60 psi or more–a standard RO unit will usually rise to the occasion and supply plenty of water pressure for the refrigerator. With low city pressure or with well systems that have variable pressure, however, the RO unit may need some help.
Various devices are used to enhance pressure output of RO units when they send water to a remote point of use like a refrigerator.
Here’s a look at the most common of these.
1. Booster Pumps. The most commonly used booster pumps are the popular Aquatec 6800 and 8800. These are electric pumps that increase the water pressure going into the RO unit. This increase in inlet pressure, in addition to making the unit run more efficiently, also increases the pressure coming out of the storage tank. However, the out-of-tank pressure is limited to about 40 psi when the storage tank is full. (There are tank switches that will run the pressure up to 60 psi, but we don’t recommend their use for most residential users.)
2. Permeate Pumps. These non-electric pumps do not increase inlet pressure but they isolate the RO unit from the back pressure created by the storage tank, allowing it to run much more efficiently. They can be installed with or without a hydraulic shutoff valve. Without the valve permeate pumps will put much more pressure into the storage tank (and this is what we recommend if your aim is to send higher pressure to your refrigerator).
3. Demand, or Deliver Pumps. These electric pumps are installed after the RO unit and they push water directly from the output of the RO unit to the point of use–e. g., the refrigerator. They can deliver water with pressures up to 80 psi. They work on demand. So,when the icemaker calls for water, or if you activate the drinking water dispenser, the pump comes on and sends water to the refrigerator.
Pros and Cons
1. The booster pump is the best choice if your RO unit is starved for pressure. For example, if you have, let’s say, tap water pressure of 40 psi. A standard RO unit will run on this pressure, but not well. What’s worse, it will put only 2/3 of that into the storage tank–25 psi or so even when the tank is “full”–so your refrigerator won’t get much water. The booster pump will run the RO unit excellently and you’ll have a strong 40 psi of pressure in your full storage tank. Booster pumps are quiet and usually trouble-free.
2. With the same 40 psi inlet pressure, the permeate pump, if installed without the shutoff system (the pump itself will take over the shutoff function) will put almost 40 psi in the storage tank. The pump will also refill the tank much more quickly when water is drawn from it. The permeate pump is trouble-free and needs no electricity. The model used with membranes that produce fewer than 50 gallons per day is very quiet. The over-50 gpd model makes a thumping noise that can be troublesome while the unit is producing water.
3. The demand pump will deliver 60 to 80 psi to the refrigerator regardless of the pressure in the tank (that is, unless the tank runs out of water, which can happen if the RO unit is a low producer). The downside of the demand pump is it won’t actually improve the performance of the RO unit, as the other pumps do, but will simply increase the pressure to the refrigerator.
Another issue is a phenomenon called “pump chatter.” This doesn’t always happen, but if it does you won’t be able to ignore it. Pump chatter can be described as the pump turning on when no demand for water is made, running briefly–a couple of seconds usually–then turning back off. This problem can be cured by installing a second RO tank between the pump and the refrigerator. The tank provides the pump with constant back pressure which keeps it turned off. It has the added advantage of giving you a couple more gallons of water, stored at maximum pressure, and ready to supply the refrigerator.
More information you might like to look at:
Fluoridation of Water Has Gone on For Decades, Therefore it is Safe
by Hardly Waite
One of the most frequently used reasons given by proponents for adding fluoride to drinking water is that fluoride has been used for over half a century and it must, therefore, be safe. Another favorite argument is that fluoridation is endorsed by government “experts” and dental professionals, so it must be safe.
If we followed this logic–that long use and recommendation by experts makes things right–we would still be smoking cigarettes to improve our health, as the American Medical Association for some time recommended. Mothers would still be advised to get their infants on formula as soon as possible, because according to the AMA in the 1950s breast milk is not adequate nutrition for babies. We could forego worries about dentists putting poisonous mercury fillings into our mouths (they have, after all, been doing it for 150 years, so it must be safe). We would still be driving cars with gasoline that spews lead into the environment. The water pipes to our homes would be lined with asbestos, since that was the piping recommended by experts for decades. Our children would be playing in the white spray emitted by DDT trucks spraying for mosquitoes, which experts once told us was absolutely safe. And, doctors would still be applying their favorite treatment, draining out blood, for virtually anything that ailed us, for the world’s leading medical experts did just that for some 2500 years.
There may be good reasons why fluoride should be added to public water supplies, but the recommendation of dentists and decades of fluoridation are not among them.
Bloodletting was still going strong at the time of this 1860 image. It was widely practiced in the 5th century BC, and it was the main treatment strategy at the time our first president George Washington was bled to death by the best medical minds of the time. Shouldn't a treatment 2500 years old and praised by the greatest physicians throughout the ages be used today?
Water Used in Food Production
People concerned about their water footprint often make an effort to turn the faucet off quickly, take shorter showers, and cut back on watering the lawn.
While these efforts are important, they ignore one of the biggest water-use culprits found in virtually every household: food and beverages.
The production of food and beverages is a water-intensive process. According to the Water Footprint Network, a single apple requires an average of 33 gallons of water to grow. Here’s what other common food and beverage products cost in terms of water consumption according to the Water Footprint Network.
Beef: Beef is one of the biggest water-use culprits in the food industry, and is one of the largest amongst meat products, utilizing an average of 1,845 gallons of water per pound of beef produced. Ninety-nine percent of the water used is for animal feed, with the remaining 1 percent coming from drinking and service water.
Coffee: Another big hitter for water use in the food and beverage industry is coffee. To create one pound of coffee beans it requires 2,264 gallons of water. This means that the average cup of coffee, using .24 ounces of coffee beans, requires 34 gallons of water to produce.
Pork: The production of meat from pigs uses a global average of 717 gallons of water per pound. From 1996 to 2005 the global water footprint for pigs accounted for 19 percent of the total water footprint of animal production in the world.
Wine & Beer: To produce one gallon of wine requires 870 gallons of water. When looking at this fact from a standard serving size perspective, 34 gallons of water are needed for 5 fluid ounces of wine. In France, Italy, and Spain, the largest wine producing countries in the world, the average water footprint of wine is 24, 24, and 52 gallons per glass of wine, respectively.
However, beer production uses 296 gallons of water per gallon of beer, requiring an average of 28 gallons of water for 12 fluid ounces of beer.
Bread: Bread created from wheat flour has a global average footprint of 218 gallons of water per pound. Most of that water use, about 80 percent, is due to the flour that is derived from the wheat, so the exact water footprint of bread depends on the origin of the wheat and how it was grown. From 1996 to 2005, global wheat production contributed 15 percent to the total water footprint of crop production in the world.
Citrus and Stone Fruits: On average, the global water footprint per pound are as follows: 67 gal./lb for oranges, 61 gal./lb for grapefruit, and 77 gal./lb for lemons. A single orange requires approximately 21 gallons of water to produce. Orange juice comes at a higher water cost, utilizing 122 gallons of water to produce one gallon of orange juice. Plums require 261 gal./lb, apricots 154 gal./lb. and peaches 109 gal./lb. Apples, bananas, grapes, and kiwis all take less than 100 gal./lb. Strawberries, pineapple, and watermelon require less than 50 gallons of water per pound of fruit.
Potato: The global average water footprint of a potato is 34 gallons per pound. China, the largest potato producing country in the world, contributed 22 percent to the total water footprint of potato production in the world.
Source: KLa Systems
Here are just a few of the many articles about water issues that are available every day from the Pure Water Gazette
website. Visit the site regularly to keep up with the latest happenings in the fascinating world of water.
Health Risks from Hurricane Harvey
The top water news story of August and probably for the year is, of course, the flooding of southeast Texas and southwest Louisiana that resulted from Hurricane Harvey. Health officials are warning residents of the health dangers they could face as floodwaters rise and drinking water supplies are compromised in the wake of the hurricane-turned-tropical storm. Floodwaters are expected to carry pathogens such as E. coli, Shigella, and Legionella. The Texas Department of State Health Services also warned of the risk of tetanus, which could enter the body through open wounds that come in contact with floodwater.
New Zealand experiences increase in E. coli and nitrates.
New Zeland is experiencing an alarming increase in E. coli and nitrate intrusion into groundwater due to the dramatic rise of the number of dairy cows in the country. Recent testing shows polluting nitrates in groundwater increased by an alarming 25%.
California water diversion tunnel construction is a costly project.
The massive water diversion tunnels, proposed to be built under California's Sacramento-San Joaquin Delta, are an expensive understaking. $17 billion is the latest working estimate. The local water utilities that must ultimately pay the bill are only weeks away from deciding whether to support the project.
EPA has not yet issued a lead standard despite what happened in Flint, MI.
In spite of the urgent need for a rule on the water contaminant, lead, the EPA has not yet issued its long-awaited lead standard. Lead contamination was brought to public attention by the Flint, Michigan lead crisis and a ruling on lead will help guide public water suppliers. Don't hold your breath. The current administration has not yet nominated an assistant administrator for water, who would normally make the final call on the contents of a rule.
A California state panel has decided to drop the maximum contaminant level (MCL) for hexavalent chromium, also known as chromium-6.
Chromium-6 gained notoriety when it was targeted by famed environmentalist Erin Brockovich. A Superior Court ruling invalidated the standard. As a result, the MCL for chromium-6 in California will return to 50 ppb. The Federal standard is 100 ppb. Previously, the standard was 10 ppb in California.
One source says that Houston's drainage grid is "so obsolete it's unbelievable."
The massive flooding in Houston after Hurricane Harvey provides a tragic lesson in what happens when natural drainage systems can't cope with overdevelopment. The metro area - fifth largest in the United States - has 2,500 miles of drainage canals and bayous that haven't been substantially improved or enlarged since the 1930s.
Follow daily water headlines and links to full articles from Environment Health News at the Pure Water Gazette.
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