The Pure Water Occasional for September 30, 2016
In this early Fall Occasional, you'll learn which shower filter makes you sing better, what a developing country cannot be, what is the MCL for potato chips, which countries have water infrastructure superior to that of the US, which famous lake has a bathtub ring, and what was found in the McMillan Reservoir. Meet Kelly Reynolds, Ralph Nader, Joan Rose and Damian Gjiknuri. Hear about microbes, triclocaraban, Chromium 6, biofilm, THMs, HAAs, DPBs, TFMs and Coca Cola. Learn about the 8-year boil water advisory at "Bay of Quinte" Mohawks, the final barrier, the standoff by the Standing Rock Water Protectors, illegal cesspools in HI, toilet reefs in New York, plus the controversy over the Vjosë River. And, as always, there is much, much more.
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We'll start this issue with a perceptive article by an author familiar to the water treatment industry, Dr. Kelly Reynolds of the University of Arizona. Kelly writes frequently on public health issues relating to water and the microbial aspects of water treatment. She is very skillful at presenting technical issues in a way that can be understood by those, like me, who are less technically prepared. The article below challenges our misconceptions about the superiority of US public water delivery infrastructure as compared with that of many other countries. -- Gene Franks.
Eliminating Chlorine Residuals from Tap Water
By Kelly A. Reynolds, MSPH, PhD
Drinking water from the tap is not sterile but is regulated to a level of acceptable risk so that infections from microbial exposures and illnesses from chemicals occur at very low levels. In the US, acceptable risk goals are set at one infection per 10,000 persons per year for microbes and as low as one in a million cases of cancer from chemicals, including added disinfectants. The question is how to ensure the safety of drinking water considering that common water treatment protocols inherently create additional health risks. Recent studies compare differences among various countries in water quality management, while exploring whether or not carcinogenic chlorine residuals can be safely excluded from municipal tap water supplies.
Water treatment in developed countries
Microbial contamination of drinking water post-treatment is a major concern for municipalities. The US has relied on a multi-barrier approach to drinking-water treatment, so that the chain of treatment applications can make up for any upstream deficiencies. Following source protection and municipal treatment, the final step in US water treatment is secure distribution to consumer taps. Ideally this is accomplished with clean, contained distribution piping. Unfortunately, the US distribution system is aged, leaky and plagued with biofilm formation, offering nutrients and protection to harmless and harmful microbes alike. Thus, the addition of a disinfectant residual within the distribution system is standard protocol.
Worldwide, many countries (including the US and the UK) require municipalities to add disinfectants such as chlorine or chloramine to the distribution system. This action creates the need to manage DBPs via rapid circulation in the system or water storage practices to minimize stagnant water zones where disinfectants are further added to retard microbial growth.
Other countries (including the Netherlands, Switzerland, Austria and Germany) do not rely on disinfectant residuals in the distribution system. But how can these countries ensure safe drinking water at the tap without using this common final barrier? The answer to this question lies in the system engineering that is designed to provide more advanced water treatment pre-distribution, effectively reducing biodegradable compounds and biofilm production. A reduced biofilm means reduced microbial growth and pathogen survival in the pipes. In countries that do not use residual disinfectants, distribution infrastructure is well-maintained and managed to utilize smaller pipes, rapid circulation and proactive flushing, combined with monitoring and rapid repair practices.
Pros and cons of the chlorine residual
Disinfection of water with chlorine has been touted as one of the greatest public-health interventions of the century, preventing epidemic waterborne outbreaks such as cholera, typhoid and dysentery. Water disinfection, however, impacts the sustained microbial population (i.e., the system’s microbiome) and general water chemistry, resulting in both positive and negative changes relative to water quality and safety.
DBPs are created during the production of drinking water when chemicals such as chlorine, ozone, chloramines, etc. react with natural organic materials, bromide, iodide and other manmade compounds. The resulting products (more than 600 identified), including THMs and HAAs, are toxic to humans and animals and have been reported in drinking-water systems worldwide.
Corrosion and adverse taste are other undesirable byproducts of chlorine residuals in tap water. Although little information exists on the potential toxicity of DBPs in drinking water, exposures have been linked to a variety of health issues, including liver, kidney and central nervous system problems. Epidemiological studies have associated lifetime exposure to chlorinated water with increased risk of bladder and colorectal cancers.(1) The trade-off of not using disinfectant residuals, however, could mean an increased risk of exposure to microbial pathogens.
Contamination in the distribution system occurs due to breaks, leaks, cross-connections, pressure differentials and other events leading to intrusion of hazardous microbes and chemicals.(2) At least 20 percent of distribution mains are reported to be below the water table and all systems have submerged pipes at some time throughout the year which provides additional opportunity for intrusion of exterior water under low- or negative-pressure conditions. Negative hydraulic pressure can draw pathogens from the surrounding environment into the water supply where residual disinfection efficacy is uncertain and variable due to changes in water age, residence time, flow velocity, etc. Outbreaks occur following external contamination in the distribution system despite the presence or requirement of residual disinfectant. Research suggests that typical residual chlorine levels (0.5 mg/L) do not provide significant inactivation of all pathogens during intrusion events, especially protozoan and viral pathogens.(3)
Can the US eliminate a chlorine residual in tap water?
Numerous studies suggest that the presence of chlorine residual does little to prevent waterborne outbreaks. A comparison of use/non-use of chlorine residual further indicates that systems with a residual disinfectant do not necessarily have fewer outbreaks.(4) Elimination of a chlorine residual in the US is unlikely given the significant lack of investment in infrastructure maintenance. Compared to the Netherlands, which has recently replaced much of its distribution piping, the US distribution system is decades older and in dire need of repair. While researchers conclude that delivery of water with the same safety level is possible and that the US should move toward a disinfectant residual-free system, a whole new set of safeguards must first be in place. Such modifications will substantially drive up the cost of drinking water, a consequence other countries have accepted, given that water costs two to three times more in western Europe.(2)
The US is far from reaching a residual-free tap water supply. The trade-off of not adding chlorine and risking the consequences of acute microbial illness is currently not beneficial. Therefore, consumers should consider the benefits of keeping chlorine residuals in tap water but controlling exposures to harmful contaminants at the tap. The most widely applied POU water treatment for DBP removal is activated carbon filtration. NSF-certified POU devices are required to remove 95 percent of a 300 µg/L chloroform influent challenge concentration, resulting in a 15-µg/L maximum effluent concentration. In the US and countries with similar treatment design, POU devices offer the best available treatment at the tap to mitigate DBP exposures, particularly given system variability and the uncertainties of future municipal treatment modifications.
(1) World Health Organization. IARC monographs on the evaluation of carcinogenic risks to humans
(2) Rosario-Ortiz, F. et al.
How do you like your tap water? Science
, 351, 912–4 (2016).
(3) Reynolds, K.A.; Mena, K.D. and Gerba, C.P. Risk of waterborne illness via drinking water in the United States. Rev. Environ. Contam. Toxicol.
192, 117–58 (2008).
(4) Rosario-Ortiz, F. and Speight, V. Can drinking water be delivered with-out disinfectants likechlorine
and still be safe? The Conversation
(2016). at Chlorine
Available as a gas, as a liquid in sodium, hypochlorite, or as a solid in calcium hypochlorite, chlorine is widely used in the disinfection of water and as an oxidizing agent for organic matter, iron, hydrogen sulfide, etc. It is. Chlorine reacts with organics in water to form trihalomethanes (THM) that can cause cancer." href="http://www.wcponline.com/glossary/chlorine/" style="box-sizing:border-box;transition:all 0.1s ease-in-out;color:rgb(0, 0, 0) !important;text-decoration:none !important;border-bottom:1px dotted rgb(0, 0, 0) !important;">chlorine-and-still-be-safe-55476>
About the author
Dr. Kelly A. Reynolds is an Associate Professor at the University of Arizona College of Public Health. She holds a Master of Science Degree in public health (MSPH) from the University of South Florida and a doctorate in microbiology from the University of Arizona. Reynolds is WC&P’s Public Health Editor and a former member of the Technical Review Committee. She can be reached via email at firstname.lastname@example.org
Scientists are protesting the damming of "the last big, wild river in Europe outside Russia"
The Vjosë, the last big, wild river in Europe outside Russia, is in danger of being dammed
"A developing country cannot be a museum."
Europe’s last wild river is about to be tamed. But it won’t go without protest.
More than 200 scientists from 33 countries called for the Albanian government to halt plans to construct the first dam on the Vjosë, which flows out of northern Greece through remote Albanian mountain canyons to the Adriatic Sea.
Scientists say the river is of “global significance," particularly for birds that breed on the huge islands downstream of the proposed 25-metre-high dam at Poçem. Once completed, the dam will dictate flows downstream according to electricity demand rather than the needs of river ecosystems.
“The Vjosë is the last big, wild river in Europe outside Russia,” says Ulrich Eichelmann of campaign group RiverWatch, which organized the scientists’ petition to save the river. “We are trying to stop these projects and instead establish the first European Wild River National Park.”
The river already has a small dam on one of its Greek tributaries. But hydrologists say its flow downstream through Albania remains mostly unchanged and its ecology largely unexplored.
Despite past election pledges to protect the river, the government in May awarded contracts to Turkish companies to build the dam. Energy minister Damian Gjiknuri told news agencies in July that the government was determined to proceed. “A developing country cannot be a museum,” he said. “Hydropower has drawbacks, but every development has a cost to the environment.”
Development also threatens a major body of freshwater in neighbouring Macedonia, where Europe’s oldest lake, Ohrid
, and its unique ecosystem is at risk because of tourism.
Just Get Yourself a Reverse Osmosis Unit and Stop Worrying
by Gene Franks
I spend a good part of most days talking on the phone about water treatment and listening to people's concerns about water quality issues. Many calls focus on the perennial items--contaminants that are in the news for awhile, then fade away, then come back strong when a new article or study makes the newscasts. These old stand-bys include lead, chloramines, chlorine, fluoride, arsenic, chromium, MTBE (this one is dying), nitrates, perchlorate, pesticides, VOCs, and "pharmaceuticals." Although I don't often say it in so many words, the sum of my advice in regard to drinking water is usually just "put a good reverse osmosis unit under you kitchen sink and stop worrying about the particulars." Instead of trying to determine if perchorate is in your water and if so is it at a level you can safely consume or fretting about whether you can trust the EPA's suggested allowable for lead or arsenic or speculating about if the nitrate level in your tap water is going to continue going up, install an undersink RO unit. Instead of worrying about all these individual concerns and all the emerging contaminants like the leavings of the teflon industry (a current hot item) and the contaminants that are yet to be discovered and others that may never be discovered, simply install a relatively inexpensive drinking water treatment that is the best known solution for almost all water treatment problems. That is the message of the article that follows: Don't expect the water provider to solve all the problems. Point of use treatment--what water treatment professionals often call "final barrier" treatment--is the sensible answer for drinking water. RO works.
"Most of the time no one is watching most of the water for most of the contaminants."
by Hardly Waite
Since Chromium 6 has been much in the news and on the public mind this month, we're reprinting a piece from a 2010 Occasional that speaks to the issue of regulation of "new" contaminants while focusing attention on the regulation of Chromium.
In late 2010 an environmental group revealed that deadly hexavalent chromium is present in the water of many US cities. Americans were shocked.
Actually, what's new with the hexavalent chromium issue isn't that Chromium-6 has suddenly been spilled into US water supplies. What's new is that someone told us about it.
Chromium-6 is only one of countless chemical contaminants that find their way into water but don't get much public attention. In the 1980s I read a perceptive article on the subject that said, "Most of the time no one is watching most of the water for most of the contaminants." In 2010 there's a lot more to watch for, since new chemicals are being created almost faster than we can give them names, yet we continue not watching.
News about water quality comes and goes in the public mind. Ralph Nader made shocking revelations about water quality in the 1980s, but people soon forgot. The public has a short attention span.
Chromium-6 didn't just appear suddenly in the water supplies of 31 of the 35 cities examined. It has been there a long time. The news is that someone went to the trouble to look for it and report it. Actually, it had been looked at earlier by government agencies, but they were happy to keep its presence to themselves as long as no one brought the subject up. This isn't an uncommon event. Just this month the FDA revealed (after much prodding) that US agribusiness now drugs farm animals with 29 million pounds of antibiotics per year. Most people are aware that factory farm animals are being dosed with antibiotics and that consequently antibiotics are becoming ineffective, but the 29 million pound number is somewhat sobering. (A "shitload," Grist calls it.) Does anyone doubt that a few tons of these drugs make their way into water supplies?
Chromium is present in water as trivalent and hexavalent chromium. The problem is that trivalent chromium is not only harmless but is an essential human nutrient. Hexavalent chromium is a potent poison. The state of California, which is usually about 20 years ahead of the rest of the country in environmental regulation, is proposing a maximum allowable of 0.06 parts per billion hexavalent chromium. The EPA is currently monitoring total chromium with a maximum allowable of 100 parts per billion.
Here is the EPA's statement on chromium, which was issued after it received criticism for dragging its feet on the regulation of chromium-6:
EPA absolutely has a drinking water standard for total chromium, which includes chromium-6 (also known as Hexavalent Chromium), and we require water systems to test for it. This standard is based on the best available science and is enforceable by law. Ensuring safe drinking water for all Americans is a top priority for EPA. The agency regularly re-evaluates drinking water standards and, based on new science on chromium-6, had already begun a rigorous and comprehensive review of its health effects. In September, we released a draft of that scientific review for public comment. When this human health assessment is finalized in 2011, EPA will carefully review the conclusions and consider all relevant information, including the Environmental Working Group’s study, to determine if a new standard needs to be set.
Currently, the total chromium standard is 0.1 mg/L (100 parts per billion). Our latest data shows no U.S. utilities are in violation of the standard.
Now, to give an idea of how close to agreement are the two expert views—the California standard vs. the EPA standard—notice first that the EPA is measuring "total chromium" and California is measuring only chromium-6. Note, too, in case you haven't, that the allowable numbers are not even in the same galaxy.
To sort all this out, image that, since we know that our potato chip intake should probably be limited, you consult a nutritional expert to find out how many bags of potato chips you can safely eat each month. His answer is one. You then consult a second expert whose answer is that you can safely eat a combined total of 1667 bags of potato chips and apples. The experts then take a survey of Americans' eating habits. Expert #1 finds that 31 in 35 are violating the one bag per month standard for potato chip consumption, but expert #2 concludes that all is well because "no Americans are violating the combined potato chip and apple standard" by eating 1667 per month. By standard 2 you can safely eat 55 bags of potato chips (and no apples) per day.
That's no more absurd than the advice we're getting from the combined wisdom of California regulators and the EPA. The numbers are radically different and they're counting different things.
The official allowable for chromium-6 will, after months or years of negotiation, eventually be set most likely somewhere between the extremes of 0.06 ppb and 100 ppb. The number will not be arrived at scientifically but will result from a political negotiation that considers the interests of manufacturers and sellers of products that use chromium, city water departments, environmental advocacy groups, wastewater processors, and a host of politicians who represent the interests of a host of lobbyists who are being paid by everyone from mining companies to state governments.
Each of these non-expert entities will employ its own set of experts who will rely mainly on the mysterious "science" of animal studies to prove its point. Animal studies, a science of roughly the same exactitude as having soothsayers examine the intestines of sacrificed goats, will conveniently prove what each of the interested parties wants proved. The final magic number, the amount of chromium-6 we can safely be exposed to, will depend mainly on the number of Republicans vs. Democrats on the committee.
Recent Water News
From this issue on, we plan to report current water news items without links to source. There are several reasons. One, it's a lot easier for us. Two, we've found that readers seldom click on the links. Three, many news sources move or take down articles fairly quickly, making the links useless in a short time. Dead links suck. Four, search sites work so well now that if you want to find the source article it's easy to do by just pasting a keyword or two from our item into a search bar. Five, I've forgotten what the last reason was, but trust me, it was a good one.--Hardly Waite.
With the western US drought it its fifth year, Lake Mead sank to its historic low. The "bathtub ring" shows the dramatic decline of the water level.
Coca Cola announced that it now replenishes as much water worldwide as it draws from natural sources to fuel its production. Exactly how this is accomplished is not clear.
August 28 to September 2 was World Water Week in Stockholm. Joan Rose received this year's Water Quality Champion prize.
A body was recovered from the McMillan Reservoir that provides much of the drinking water for Washington, D.C.
Over the past two years Texas has received record-breaking rainfall, recording the most rain since 1942.
The FDA issued a rule banning 19 specific chemicals in liquid and bar soaps, including triclosan (commonly used in liquid soap) and triclocarban (used in bar soap). The agency says manufacturers have not shown that these products are any more effective than plain soap and water in preventing illness or stopping the spread of certain infections.
A group of dairy producers in Kewaunee County, Wisconsin announced that it will pay more than half the cost of drinking water purification systems for residents whose wells have been polluted by animal waste.
Vermont has lowered the drinking water allowable from 35 to 3 parts per million for the pesticide TFM which is used to control the sea lamprey in state waters.
Six members of a Sioux tribal group called Standing Rock Water Protectors were attacked by dogs and pepper spray while demonstrating against continued development of the Dakota Access Pipeline.
The EPA has fined the U.S. Army $100,000 for continuing to operate illegal cesspools in Hawaii.
The U.S. Department of Agriculture (USDA) is making investments to improve water and waste infrastructure for 168 small towns across the country, including the Commonwealth of Puerto Rico. The investmen totals $283 million.
New York state has an ambitious project that recycles old toilets to create oyster reefs. The reefs will not only serve as habitat for oysters but will also provide erosion protection for wetlands and natural filtration of sea water.
A Florida teenager has won an annual open-water swimming competition off the Florida Keys. Seventeen-year-old Noah Zhang of Jupiter, FL won the Swim for Alligator Lighthouse open-water swimming competition, completing the 9-mile swim in 3 hours and 46 minutes.
About 980 million liters of contaminated water leaked into Florida's main underground source of drinking water after a huge sinkhole opened up under a phosphate fertilizer plant near Tampa.
A small Canadian town, "Bay of Quinte" Mohawks in Tyendinage, opened a new water treatment plant ending an eight-year boil water advisory.
Black and White Now Available with GRO Membrane
Our Black and White RO units, all styles, now come with Pentair's GRO 50 percent recovery membrane as an optional upgrade. This low-cost upgrade membrane can save incredible amounts of water as compared with conventional membranes.
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Thank you for reading. Please come back next week.
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