An Email Publication About Water and Water Treatment February 2011 |
In this brand new Occasional you'll hear about a private waste dump in South Dakota, cation and anion exchangers, the Circle of Blue, and gasoline-contaminated water in Baltimore. Perchlorate, fracking, phosphorous overuse, mysterious calcium slime, and a highly touted "device" called SAFL Baffle. Learn how many children die each day from preventable water-related illnesses, how many small dams there are in the US and how many large dams there are in China, plus the names (and addresses) of the ten US cities with the worst drinking water. As always, more about hexavalent chromium. On top of that, you'll hear about a new law against shark fin possession and learn how fish are being used as water testing devices. You'll hear more than you want to know about what filter carbon does and doesn't, how to remove cryptosporidium, giardia, and radon from water, and, as always, much, much more. The Occasional is overseen by Pure Water Gazette editor Hardly Waite. Thanks for editorial assistance for this issue by Beth Rutter. |
While you were filling out your Valentine cards and shivering, a lot of important things happened in the world of water. To hear all about it, read on.Water News for February 2011The EPA announced that it is establishing a drinking water standard for the rocket
fuel perchlorate. California's lush Westlands Water District is facing a water crisis that threatens one of the nation's prime sources of agricultural products. The cities of Delaware and Marysville, both in Ohio, have discovered that treating their municipal water supply with reverse osmosis leads to complex and costly disposal problems.
A Clemson University soil expert was brought in to determine
the safety of
a Pelion, SD private waste dump that has for 22 years been discharging human waste and restaurant grease onto the ground. Water
in the area is poisoned with nitrates. The U.S. Environmental Protection Agency (EPA)
submitted a draft study plan on hydraulic fracturing for review to
the agency’s Science Advisory Board (SAB), a group of independent
scientists.
Gasoline-contaminated drinking water caused the closing of a Baltimore area
school.
Citizens
of Fair Play, SC protested vigorously in attempt to stop the
construction of a proposed water treatment plant.
Thieves
dug a tunnel under concrete to steal tens of thousands of dollars
worth of equipment from the Hamilton City Council's water treatment
plant. Among the stolen items were 10 bronze
water pump impellers. Two of the impellers were valued at $60,000 to
$80.000. Lawmakers in California are considering a law to ban the possession of shark fins. New York City has undertaken a mammoth tunnel system. It links with a 120-year-old aqueduct and a one-of-a-kind filtering plant in the Bronx. A major engineering feat, it is designed to provide safe and excellent water for the city for years to come. Article highly recommended. A judge in a small
jungle town in Ecuador ordered Chevron to pay more than $9 billion in
damages, finding the energy giant responsible for the oil pollution
that has fouled a stretch of land along Ecuador's northern border. Chances that
Ecuador's poor, whose land has been ruined by US oil exploitation,
will actually collect any damages?
Virtually zero. The world is running
out of phosphorus, largely because of industrial and agricultural
overuse.
The
outrageously wasteful overuse of phosphorus-based
fertilizers has created a major source of water contamination.
Research in Great
Britain concluded that children with eczema were not helped by
bathing in ion exchange softened water.
A Nevada lawsuit charges that wells once used for drinking water are polluted with uranium, arsenic and other metals because of decades of chemical leaks from a mine owned and operated by British Petroleum. High tech devices called fish are an old standby in monitoring water
quality.
A Japanese company has developed a bicycle water purifier that
can treat up to 5 liters per minute.
The increased use of hand pumps in rural India has lead to increased use of ground water which in turn has caused an increase in fluoride intake which in turn has caused a spurt in fluorosis disease in several Indian states. Limb deformities [skeletal fluorosis] have been more pronounced among the young. Scientists in Minnesota have developed a device that is said to prevent harmful sediment from entering lakes and streams. The device, called SAFL Baffle, works by slowing down water runoff, thereby preventing the water from picking up harmful sediments. It is pictured below. See if you can figure out how it works. (We can't.)
The Administration's new budget proposes a13% decrease in funding for the EPA. There's a new list
of the ten American cities with the worst drinking water. The EPA is
considering a study of fracking in our home county. We hear complaints almost daily from local well owners.
The wastewater treatment system of Jerome. ID has been taken over by a mysterious slime.
More About
Hexavalent Chromium
|
Is Carbon a good treatment for ...? |
Answer |
Comment |
Yes |
This is what coconut shell carbon is best at. |
|
Yes |
Best and often the only treatment. |
|
Yes |
Best and often the only treatment. |
|
Herbicides |
Yes |
Best and often the only treatment. |
No, with qualifications. |
Carbon is not a recognized treatment for bacteria, although carbon blocks can be made so tight that they screen out bacteria. Silver impregnated carbon is marketed as "bacteriostatic." This does not mean that it purifies non-potable water but that the added silver can inhibit the growth of bacteria in the carbon bed. The same is true for KDF, which is said to have "bacteriostatic" properties. |
|
Cysts (Giardia and Cryptosporidium) |
No, with qualifications. |
However, many carbon block filters have cyst certification because they are tight enough to screen out cysts effectively. |
Inorganics |
No, except mercury. |
Carbon block filters, however, are often engineered to remove lead by the adding a lead removal resin to the carbon. Arsenic reduction media can also be added to carbon filters. |
Radionuclides |
No, with qualification. |
This is a difficult classification. According to the EPA, "Approximately 2,300 nuclides have been identified; most of them
are radioactive." The two most frequently at issue in water treatment, Radon and Uranium, are included separately in this listing. |
Yes |
Aeration is usually preferred to carbon filtration because the spent carbon itself becomes hazardous waste. |
|
Hydrogen Sulfide (Rotten Egg Odor) |
Yes, with qualifications. |
Lifespan of carbon can be limited if the H2S is not pretreated with an oxidizer. Catalytic carbon is superior to standard for H2S treatment. |
Yes, with qualification. |
Backwashing standard carbon filters remove pre-oxidized iron. Catalytic carbon can remove reasonable amounts of unoxidized iron. |
|
pH correction |
No, with qualification. |
Almost anything done to water affects pH, but carbon is not used to raise or lower pH. |
Calcium and Magnesium (hardness) |
No |
Only water softeners, reverse osmosis, and distillers actually remove hardness. |
Sodium |
No |
Only water softeners, reverse osmosis, and distillers actually remove sodium. |
No |
Only reverse osmosis, distillers, and anion exchangers affect nitrates. |
|
No, with qualifications. |
Carbon sometimes removes fluoride, but it is not a reliable fluoride treatment. A specialty carbon made with animal bones (Bone Char) is used in some parts of the world to remove fluoride. |
|
Taste and Odor |
Yes |
Carbon is the unchallenged best treatment for most taste/odor problems. Carbon filtration improves the taste of most waters. |
Yes, with qualifications. |
Macropore carbon (usually made of Eucalyptus and currently hard to find) is an effective treatment for tannins. Lignite based carbon is also used for tannins. Standard carbon may help. |
|
TDS (Total Dissolved Solids) |
No |
Carbon does not reduce dissolved minerals. In fact, carbon filtration may add slightly to the TDS reading. |
No |
Only when accompanied by arsenic reduction resins. |
|
No |
|
|
MTBE (gasoline additive) |
Yes |
Coconut shell carbon is preferred. |
Yes |
Much longer contact time is needed for chloramine than for chlorine. Catalytic carbon is superior to standard carbon for chloramine reduction. |
|
Uranium | No | |
Yes |
Carbon converts chlorine to harmless chloride. This is what carbon is best at. |
If there is a question about how to reduce a specific water contaminant, you can find information on most in the Occasional's Water Treatment Issues section.
The Ups and Downs of Filter Cartridgesby Pure Water AnnieGood and sincere advice from the Occasional's Technical Department. Here Pure Water Annie demystifies one of the great mysteries of filter cartridge replacement: Which end goes up? One of the most frequent calls we get from customers who are replacing cartridges in their filters or reverse osmosis units concerns the up and down of installation--which end goes up in the housing. Here's a picture of various types of filter cartridges that I'll use to explain: In this discussion we're skipping the obvious. In the picture, the candle style (includes Doulton Candles, Multi-Pure cartridges,and some carbon blocks) and the Q Series cartridge screw into their housing. You screw the part with threads into the other part with threads. No explanation should be needed. The Inline cartridge has no housing, but you need to observe the direction flow arrow (some are hard to find). This leaves us the cartridges that go in standard housings. Standard cartridges fall in two categories: radial flow and axial flow. Radial Flow Cartridges have no up or down. The 4.5 X 20 is a radial flow carbon block. Water flows from the outside of the cartridge though the wall to the center, then exits the housing from the center of the cartridge. Cartridges marked 9.75 X 4.25 (a "pleated" sediment cartridge) and 2.5 X 20 (a "melt blown" sediment cartridge) are also radial cartridges. Water flows from the outside, through the wall, and exits from the center. With these cartridges, it doesn't matter which end goes up in the housing. The most important thing is to keep them centered so that the knife-edge seals built into the filter housing can seat properly. With Axial Flow Cartridges, the correct up and down orientation must be followed or the cartridge simply won't work. An axial flow cartridge is one in which the water enters one end and flows through the entire length of the cartridge to exit at the other end. The blue cartridge in the picture is the only standard axial. Axials, which are normally granular media filters, may have an end gasket on only one end (some have two) and one end (the one with the gasket) is often smaller in diameter. The "which end goes up" difficulty comes from the facts that manufacturers have no standard way of labeling and the axial cartridges can be used in undersink-style housings and countertop-style housings. The cap of an undersink filter serves the same function as the base of a countertop filter. Here are the rules: The narrow end of the axial filter goes toward the cap or base. The wider end of the cartridge. which often has slits for water to enter around its perimeter, goes into the "sump"-- the long part of the filter housing. Manufacturers of cartridges, for some reason, assume that the cartridge will be installed in an undersink (cap up) filter. Their labels often say, "This end up." This really means that this end goes up in an undersink filter but down (toward the base) in a countertop filter. The best news about all this is that if you get the cartridge in upside down, it won't hurt do any damage, and you'll know it right away because no water will go through the filter. If water won't flow through the axial cartridge, you have it upside down. How to tell an axial from a radial. The easy way is to look through the center hole as if you were looking through a telescope. If you can see through,it's a radial flow. If you can't it's an axial.
On Dams and Some Other ThingsElevation below sea level of the Dead Sea, the lowest place on Earth: 1400 ft. Feet by which groundwater levels in Mehdigan, India have dropped since Coca Cola, promising great benefit to the city, began its bottled water operation there: 40. Number of Gandhre, India villagers whose water needs could be met by the water that Coca Cola withdraws for its bottled water operation there: 75,000. Fraction of participants in a 2007 CBS News-sponsored taste test who preferred the taste of tap water over bottled water: 2/3. Percentage of bottled water sold across state lines that is regulated by the FDA: 30 to 40 percent. Barrels of oil required each year to support the annual U. S. plastic water bottle production: 17,000,000. Number of automobiles that could be fueled with this oil: 1,000,000. Percentage of US plastic water bottles that are not recycled: 86%. The year that Hoover Dam, considered the first modern dam, went into service: 1935. Square miles covered by the state of California: 163,707. Square miles covered, collectively, by the world's dam reservoirs: more than163,707. The estimated number of large dams around the world: 50,000- 54,000. Number of large dams in China: 22,000. Number of large dams in India: 3,600. Number of small dams in the United States: 99.000. The amount of the world's food production made possible by the water that dams store: 1/6.
Estimated number of environmental consequences that the tiny African country of Lesotho has suffered because of changes of water flow caused by its dam: 20,000. According to the World Commission on Dams, total number of people who have been driven from their homes by dam construction:: 40 – 80 million. Number of people killed by a 1967 Indian earthquake blamed on the weight of a dam's reservoir: 180. The number of people who were drowned in 1963 by a wave created by seismic activity blamed on the filling of a dam reservoir in Vaiont, Italy: 2,600. Number of unsafe dams in the US, according to a 2008 civil engineering study: 3,500. Percentage of dams that are privately owned in the United States: 56% Amount that the Chinese government's Exim bank has loaned for the Merowe Dam project in Sudan: $520 millions. Number of poor Sudanese that the Merowe Dam is expected to leave without homes: over 50,000.
Suggested reading this month from the Pure Water Gazette's archive: Whose Water Is It? Water Rights in the Age of Scarcity, by Peter Gleick. Model 77: "The World's Greatest $77 Water Filter" Occasional's Fair Use Statement Please Visit |
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