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  • Hepatitis A: What You Need to Know

    Hepatitis A is the milder form of hepatitis, which causes inflammation of the liver. The infection is caused by a virus, and is transmitted through the ingestion of contaminated food and beverages.  Water is a common transmission method, and the infection is often seen in places with poor sanitation, such as in developing countries. Regions with the highest rates of hepatitis A include northern and southern Asia, Africa, southern and eastern Europe, and some parts of South America.

    Most people in the US who become infected with hepatitis A, contracted the virus after traveling to a country where the disease is common. Transmission occurs via the stool-to-mouth route, or when a person ingests food or beverages contaminated by human feces carrying the hepatitis A virus (HAV).


    Infection with hepatitis A, unlike infection with the other types of viral hepatitis (B and C), does not bring about chronic liver disease, and is hardly ever a fatal condition. Its symptoms, however, can be debilitating and include: loss of appetite, malaise, fever, nausea, abdominal discomfort, diarrhoea, dark-colored urine, and/or jaundice. Only 10% of children develop jaundice, and those younger than six years often do not exhibit symptoms. More severe symptoms are often experienced by older children and adults; in adults -- at least 70% develop jaundice. Recovery may take several weeks or months, but most do not develop complications.

    In places where hepatitis A outbreaks are common, children are the most at risk of acquiring an HAV infection. Those who have not been infected before, or have not been vaccinated, including travellers to regions where HAV infections occur frequently, are also at risk of contracting the disease. Blood transmission can occur when a needle used by, or on, an infected person to inject drugs is reused by, or on, an uninfected person. Transmission through sexual contact is also possible when the HAV infection is acute. The most common mode of transmission is when food or beverage contaminated with an infected person's faeces is ingested by an uninfected person. In places where water is not treated properly or is contaminated by sewage, waterborne outbreaks are common.

    Treatment of hepatitis A mostly focuses on ensuring comfort, and adequate nutrition of the patient; those who require hospital care receive supportive therapy, including intravenous fluids and pain medications. The majority of people who get infected with HAV recover without complications, within a few weeks. Proper sanitation is also critical to prevent outbreaks. People who have already contracted HAV usually develop lifelong protection against re-infection.

    Vaccines for hepatitis A are readily available worldwide, and those who plan on traveling to high-risk countries should receive proper vaccinations beforehand. It is also advisable to only drink boiled, bottled, filtered, or chemically treated water when traveling in high-risk countries. Tap water should also be avoided when brushing teeth, as should ice cream, juices, unpasteurized milk, and ice from street vendors. Travellers should also avoid eating fruits, raw or undercooked vegetables, shellfish, and any other food that may have come into contact with contaminated water.

    Where tap water is the only water available for drinking and brushing the teeth, boiling the water is most effective way of killing pathogens. Alternatively, a traveler can buy chemical disinfectants and/or a water filter to purify tap water. When traveling in countries with a dubious water supply, we recommend that travelers filter drinking water using a good quality drinking filter such as the Travel Berkey, or a light-weight portable alternative, such as the Go Berkey Kit, which is perfect for travelers. Both these water filters will remove disease causing pathogens, as well as many other types of contaminants that may be lurking in the water and could damage your health.

  • Turbidity can Signify the Presence of Harmful Water Contaminants

    Have you ever wondered why at times the water flowing from your faucet looks so cloudy; and when this happens, are you concerned that it may pose a health risk? The level of cloudiness in drinking water is referred to as turbidity, which in essence is the measurement of relative clarity of water. Water contains suspended particulate matter, such as silt, clay and other particles, which refract light. When there are high levels of particulate matter suspended in the water, light can no longer penetrate into the water, and consequently it appears cloudy.

    How can Turbidity Affect Health?

    Turbidity affects the aesthetic quality of water, and as it does not directly impose any health risks, it is only considered a secondary water contaminant. However, cloudy water could indicate the possibility that other pollutants, such as Cryptosporidium and Giardia which do pose a health risk, are present. Turbidity is caused by particles that are held in suspension in water. These particles serve as both a source of food and shelter for microbes. Water that is very turbid can reduce the effect of chemical disinfection treatments used to kill pathogens that may be present in the water. Therefore, it is recommended that if water is to be disinfected effectively, the levels of turbidity should be reduced before treatment.


    Outbreaks of disease in the past have been attributed to sporadic incidents of high turbidity in water released from water treatment plants. While this association is not conclusive, based on the fact that when the water is turbid, micro-organisms are likely to be present in the water, and some of these micro-organisms can cause health problems, it is highly recommended that the necessary steps are taken to reduce turbidity in drinking water.

    Besides causing health problems, turbidity can also cause other problems in our homes, and in our environment. For instance, turbidity that is caused by inorganic materials can clog pipes, while turbidity stemming from organic materials can cause stains on clothes and other household objects.

    How Turbidity is Measured

    There are different devices that are used to measure turbidity, such as a transparency tube; a secchi disk, which is used to measure turbidity in deeper water; or a turbidity meter, which is an electronic device that is used to measure the clarity of the water. When measuring turbidity, nephelolometric turbidity units are used - as turbidity increases, the NTU also increases. While 1 NTU is the recommended standard turbidity level for drinking water, turbidity will only really be noticeable in water at levels greater than 5 NTU.

    Water Treatment Methods to Improve Water Clarity

    A good quality drinking water filter, such as the Big Berkey fitted with Black Berkey filter cartridges, can remove these suspended solids from your drinking water, producing clear appetizing water for you to drink. The Berkey water filter will not only improve the clarity of the water, but will also remove any pathogens that could be lurking alongside these sediments, to ensure that you and your loved ones suffer no ill side effects should the water be contaminated with other more harmful pollutants.

  • Recycling Fracking Fluids Will Reduce Water Use and Limit Contamination Risks Experts Say

    After conducting a thorough analysis of fracking water produced by three shale gas reservoirs, scientists from Rice University recommend that environmentally-friendly measures are initiated for treating and reusing the wastewater produced.

    The scientists advocate that instead of disposing of fracking wastewater produced during fracking operations, this water should be recycled using advanced treatment methods, for reuse in the fracking process. According to Andrew Barron, who led the study which was recently published in the scientific journal, Environmental Science: Processes and Impacts, this would not only reduce the risk of accidental spillage, and thus reduce the risk of contaminating underground aquifers and local drinking water resources, but would also save millions of gallons of water every year.


    Even though the Texas fracking industry only uses around 1.5% of the volume of water used by farmers and municipalities, this still equates to around 8.5 million gallons spread between the two main shale formations in Texas, which according to Barron, places considerable pressure on communities living nearby.

    The researchers initially analyzed fracking fluids that were pumped through shale formations in New Mexico, Pennsylvania and Texas. Barron together with lead author, Samuel Maguire-Boyle, discovered that the fluids produced by fracking (both gas-produced water and shale oil) do not contain significant amounts of potentially hazardous polyaromatic hydrocarbons, but do contain small concentrations of other chemical compounds, which they believe the fracking industry should phase out by developing non-chemical alternatives for treating fracking fluids and the wastewater produced.

    Currently, wastewater from fracking fluids pumped into a gas well is either pumped out to a closed fluid-capture system or it is pumped back underground for disposal. According to Barron, neither of these options offers an effective long-term solution.

    “Ultimately, it will be necessary to clean produced water for reuse in fracking,” he said. “In addition, there is the potential to recover the fraction of hydrocarbon in the produced water.”

    According to Barron, fracking fluids are comprised of 90% water, with 8-9% consisting of sand or some type of proppant that holds the fractures open for the oil and gas to escape, and 1-2% consisting of a variety of salts, scale inhibitors, friction reducers, gelling agents, biocides, gel breakers, and organic and inorganic acids. The organic substances may occur naturally or they may be remnants of added constituents.

    The scientist revealed that the majority of salts, minerals and organic substances contained in fracking wastewater originate from the connate fluids trapped within the pores of the underground rock, and are of little concern. However, they found that fracking wastewater also contained potentially hazardous chlorocarbons and organobromides, which likely formed as a result of interactions between large concentrations of bacteria present in the water and the chemicals or salts used in the fracking wastewater treatment process.

    According to Barron, the fracking industry often treats fracking water with hypochlorite or chlorine dioxide so that it can be recycled for reuse. However, these treatment processes can enhance the ability of bacteria to convert hydrocarbons that occur naturally into more hazardous chlorocarbons and organobromides.

    “We believe the industry needs to investigate alternative, nonchemical treatments to avoid the formation of compounds that don’t occur in nature,” said Barron.

    Journal Reference:
    Samuel J. Maguire-Boyle, Andrew R. Barron. Organic compounds in produced waters from shale gas wells. Environmental Science: Processes & Impacts, 2014; DOI: 10.1039/C4EM00376D

  • Former Navy Bases Need to Clean Up Their Act

    The initiation of a new water quality test requirement for drinking water has resulted in the closure of four major drinking-water wells, and could lead to delays in the redevelopment of the former Willow Grove Naval Air Base due to water contamination issues.

    Perfluorooctane sulfonate (PFOS) is a chemical that was routinely added to foams used for firefighting at former Naval Air bases at both Willow Grove and Warminster, both of which have been inactive for many years. Production of the chemical was phased out in the US about ten years ago, and until recently local water agencies have not been required to screen drinking water for the presence of these compounds.


    Now, local residents are concerned that their private wells may also be contaminated with PFOS, some believing that the recent surge in cancer cases in their area over the last couple of years, including leukemia, lymphoma, breast-, liver- and pancreatic cancer, can be attributed to their local water supply being contaminated with this chemical pollutant.

    The resident's fears may be well founded. Studies conducted on animals have found that exposure to PFOS can cause problems with reproduction and development, and is also associated with an increased risk of cancer.

    One resident who worked at the Warminster Navy Base in the 1950s is not surprised that the water is contaminated, as back in the day everything got disposed of underground.

    According to Karen Johnson, an EPA spokesperson, authorities have been aware of PFOS for some time, but until recently have not had the necessary lab equipment to test for the compound.

    In Warminster, recent tests have revealed that PFOS levels are three times higher than the recommended threshold in one drinking-water well, which was shut down together with a nearby well where levels just below the recommended threshold were recorded. In Horsham, two wells were shut down in August after tests revealed PFOS levels three times higher than the safety threshold at one well, and five times higher at another. The affected towns now need to import drinking-water from nearby towns to meet their needs.
    According to Tina O'Rourke, a representative of the Horsham water authority, these two wells supplied roughly 26% of the town's water, and estimated that it would take at least another year to resolve the situation, either by finding an alternative source of supply or by treating the contaminated water within the two wells.

    Perfluorooctane Sulfonate Contamination

    Perfluorooctane sulfonate is a common type of perfluorinated compound that was developed in the early 1950s and is commonly used in a variety of products, including fire-fighting foam, semi-conductors, non-stick coatings, textiles, and paper-based products. While it is no longer produced in the US, it is still abundant in the environment. The reason for this is that because the compound was developed to be resistant to water and fats, it does not readily break down in the environment. Their slippery consistency makes them difficult to screen, difficult to eradicate, and allows them to spread easily. Consequently they are abundant in the environment and have been found in the tissue of fish and other animals, including humans across the US.

    Health Impacts

    Research conducted on primates and rodents have shown that PFOS compounds accumulate in the kidneys and liver, and is associated with reproductive and developmental problems, as well as cancer. A provisional health advisory put out by the EPA in 2009 states that exposure to PFOS levels over 0.2 ppb "may cause adverse health effects in the short term (weeks to months)."

  • BPS, a Common BPA Substitute, is Just as Harmful to Humans

    If you are aware of the dangers of BPA and are actively taking precautions to avoid exposure by selecting food and beverages packed in BPA-free packaging, you may still be vulnerable to the toxins associated with BPA, as well as the health hazards.

    Bisphenol S (BPS), commonly used to replace hazardous bisphenol A (BPA) in household products, may be just as detrimental to cardiovascular health as BPA, according to the results of a new study, which were recently presented at a joint meeting held in Chicago by the Endocrine Society and the International Society of Endocrinology (ICE/ENDO 2014).

    Since research has shown BPA to have many potentially harmful effects on humans, in recent years many manufacturers of hard plastics and other consumer products have chosen to switch from BPA to a chemically similar compound, BPS, marketing these products as BPA-free.


    However, according to lead author of this study, Hong-Sheng Wang, from the University of Cincinnati, while some BPA-free products are free of bisphenols, "BPS is one of the substitutes used in BPA-free products. There is implied safety in BPA-free products. The thing is, the BPA analogs—and BPS is one of them—have not been tested for safety in humans."

    BPA is a known hormone disrupter that can disrupt estrogen as well as other hormones, however, it is unclear whether BPS also interferes with hormones.

    For this study -- which Wang refers to as an initial assessment of the effect of BPS on the primary cells and/or organs of mammals -- Wang and his colleagues tested a dose of BPS similar to that found in urine samples of humans in other studies, on the hearts of a sample of 50 rats.

    When comparing the results of rats that were exposed to BPS to the control group that were not, female rats that were exposed to BPS exhibited a rapidly elevated heart rate, which led to abnormalities in heart rhythm under stress, which far exceeded that of the control group of rats that were not exposed to BPS. Electrocardiograms showed that for female rats, exposure to BPS resulted in additional heart beats and caused the heart to race. BPS did not reportedly have the same effect on the hearts of male rats.

    To better understand the cause of these effects on the hearts of female rats, the research team looked at the muscle cells of affected rats. They discovered that BPS exposure led to abnormal cycling of calcium, which according to Wang, is a primary cause of an irregular heart beat. It is also very similar to the toxic effect that BPA has on the heart, as Wang and his team showed in an earlier study.

    The researchers attempted to prevent the heart rhythm anomalies induced by BPS in the female rats by blocking an estrogen receptor. According to Wang, their results showed that "the BPA analog BPS is not necessarily free of endocrine-disrupting activity."

    "Our findings call into question the safety of BPA-free products containing BPS," Wang concludes. "BPS and other BPA analogs need to be evaluated before further use by humans."

    Bottled water is one consumer item that is packaged in plastic bottles that often contain BPA. These chemicals can potentially leach into the contents, especially when stored for long periods. To avoid long term exposure to Bisphenol toxins we advise drinking filtered water rather spring water supplied in plastic bottles.

  • New Study Highlights the Hazards of Ingredients in Fracking Fluids

    With the oil and gas industry rapidly expanding across the country, there is rising concern regarding the hydraulic fracturing process used to extract these natural resources from deep within the ground. Environmentalists and local residents are particularly concerned about the fluids used in the extraction process, and more specifically the contents that make up these fluids.

    A new study that examines the contents of fracking fluids raises concerns regarding various ingredients contained within. The researchers who presented the results of their study at the 248th National Meeting & Exposition of the American Chemical Society (ACS) last week, found that of the approximately 200 compounds that are typically used in fracking fluids, we have very little knowledge of the potential health hazards of a third of these compounds, except that eight are known to be poisonous to mammals.

    Fracking pond

    While hydraulic fracturing has led to a boom in the natural gas industry in the US, the process, which involves pumping a solution of water mixed with a wide variety of chemicals deep into underground rock formations to force the gas and oil out of the ground, is extremely controversial. Supporters of fracking say that it is the answer to our energy woes and provides employment opportunities, and consequently offers huge economical benefits. Those against fracking, are concerned about the environmental and health consequences associated with pumping vast amounts of chemically-laden fluids into the ground, with the biggest fear being contamination of drinking water resources, particularly contamination of groundwater in subterranean aquifers.

    "The industrial side was saying, 'We're just using food additives, basically making ice cream here,'" says Stringfellow. "On the other side, there's talk about the injection of thousands of toxic chemicals. As scientists, we looked at the debate and asked, 'What's the real story?'"

    The research team conducted an extensive search of reports and databases to draw up a list of substances that are commonly added to fracking fluids. These substances include gelling or thickening agents, biocides to prevent microbial growth, sand to force open tiny fissures within the rocks, and rust inhibiting chemical compounds to prevent corrosion of pipes.

    Their analyses of this extensive list of ingredients reveals that both views are true to a certain extent -- but with some notable limitations. Fluids used in the fracking process do indeed contain many non-toxic and/or food-grade substances as the oil and gas industry proclaims, however, just because a substance is biodegradable or edible, it doesn't necessarily mean that it can be readily disposed.

    "You can't take a truckload of ice cream and dump it down the storm drain," says Stringfellow, echoing the analogy used by the fracking industry. "Even ice cream manufacturers have to treat dairy wastes, which are natural and biodegradable. They must break them down rather than releasing them directly into the environment."

    The researchers found that the majority of chemical ingredients will need to be treated before they can be released into the environment. And while the substances considered toxic were not as extensive as certain critics propose, the team identified eight ingredients, including biocides, which they consider to be of grave concern, as they are known to be especially poisonous to mammals.

    "There are a number of chemicals, like corrosion inhibitors and biocides in particular, that are being used in reasonably high concentrations that potentially could have adverse effects," Stringfellow notes. "Biocides, for example, are designed to kill bacteria — it's not a benign material."  Upon assessing the impact that fracking fluids are having on the environment, the researchers have determined that some ingredients are also toxic to aquatic organisms.

    Furthermore, for approximately a third of the roughly 190 fracking substances listed, there is very little information available regarding their chemical and physical properties or toxicity -- information that should be included on a Material Safety Data Sheet (MSDS) of potentially hazardous compounds.

    "It should be a priority to try to close that data gap," Stringfellow says.

  • New Water Borne Disease Caused by Brain-Eating Amoeba

    The dry conditions that are prevalent across the US are not only having a negative impact on the landscape and suburban lawns, it is also thought to be the cause of the sudden proliferation of a deadly pathogen, Naegleria fowleri, that thrives in warm aquatic conditions. With the hot and dry conditions experienced this summer, the water in freshwater bodies such as rivers and lakes is much warmer than it normally is, which could explain the spike in numbers of these parasites.

    The recent death of a 9-year-old girl in Kansas, who succumbed to an infection caused by the aquatic parasite after having swum in several freshwater lakes in the area, highlights the dangers of this pathogen.


    The parasite, Naegleria fowleri, is considered a sapronosis, which is an infectious disease that is caused by microscopic free-living pathogens that are found in soil and/or aquatic habitats rather than in a live host organism. The pathogen is a parasitic amoeba that enters the human body via the nose, traveling along the nasal passages and nerve fibers until it reaches the brain. It then starts to eat brain cells, resulting in primary amoebic meningoencephalitis (PAM), which affects the central nervous system. Children and young adults who have been exposed to the parasite through recreational activities in freshwater aquatic systems tend to be most vulnerable to the disease.

    A team of researchers from UC Santa Barbara whose work focuses on the transmission of infectious disease examined this infectious agent in detail; the results of their findings were recently published in the scientific journal Trends in Parasitology.

    What is a Sapronosis?

    "Sapronoses do not follow the rules of infectious diseases that are transmitted from host to host," said lead author Armand Kuris, a professor in UCSB's Department of Ecology, Evolution and Marine Biology (EEMB). "They are categorically distinct from the way we think infectious diseases should operate." This study focuses attention on this group of emerging pathogens and aims to increase our understanding of how they function.

    Legionnaires' disease -- which is caused by Legionella pneumophila, a bacterium that is transmitted in contaminated soil or aerosolized water -- is a better known example of a sapronotic disease. Legionnaires' disease is named after an outbreak of the disease among a group attending an American Legion convention being held at a hotel in Philadelphia in 1976. There were 29 fatalities out of the 182 cases reported, most of which were men.

    Sapronotic pathogens are able to survive independently in an aquatic system or even a reservoir such as a water tower that feeds an air-conditioning system. Some such pathogens, such as cholera, depend on insects to find a disease host for them. Zoonotic diseases by comparison, require a human host.

    What's the Difference Between Sapronotic and Vector Borne Diseases?

    According to Kuris, vector borne diseases that result when infectious pathogens are carried and transmitted from one living organism to another -- which could be a microorganism, an animal, or another person -- tend to be more or less virulent depending on how efficiently they are transmitted. "As a result, virulence evolves to a level where it is balanced with transmission in order to maximize the spread of the virus." However, Kuris points out that sapronotic pathogens are not restricted by such a virulence trade-off. "Transmission of a sapronosis pathogen is able to persist regardless of any changes in host abundance or transmission rates."

    To compare differences between sapronotic and conventional diseases, the research team modeled the population growth rate of 150 human pathogens. From the random selection of diseases examined in the study, a third were sapronotic -- more specifically, 12.5% of protozoan pathogens, 28.6% of bacteria, and a whopping 96.8% of fungal pathogens selected in the study were sapronotic. Kuris considers the fact that practically all the fungi are sapronotic as something worth noting.

    "You can't model a sapronosis like valley fever with classic models for infectious diseases," said co-author Kevin Lafferty. "To combat sapronoses, we need new theories and approaches. Our paper is a start in that direction."

    How to Prevent Infection

    But as climate and local freshwater systems continue their warming trend, this emerging pathogen is likely to proliferate further, posing a risk to swimmers who cool off in local rivers and lakes. To reduce the risk of infection from this rare, yet fatal pathogen, swimmers can use nose plugs to prevent the parasite entering the body.

    Journal Reference:
    Armand M. Kuris, Kevin D. Lafferty, Susanne H. Sokolow. Sapronosis: a distinctive type of infectious agent. Trends in Parasitology, 2014; DOI: 10.1016/

  • Algae Bloom and Microcystin Removal – Berkey FAQ

    Below is some information that might be helpful, with respect to the recent Algae Bloom and resulting contamination of the water supply to Toledo, Ohio: “…Cyanobacterial cells range in size from 0.5-1 μm to 40 μm in diameter…” In other words, it's a long skinny bacteria.


    Toxic microcystin bacteria float, along with a dead fish, on the surface of this lake. Toxic microcystin and cyanobacteria float, along with a dead fish, on the surface of this lake.

    Internet research seems to indicate that cyanobacteria are even larger, typically on the scale of 150 micrometers in size. While we have not tested the specific microbes associated with Algae Blooms, we have tested other pathogenic bacteria and two viruses, which are a small fraction of the size of these microbes.
    To understand the difference between the size of pathogenic bacteria and viruses, we suggest the following web link as it will give you a great visual of the difference.

    The University of Utah Cell Size and Scale Chart:

    Slide the scale at the bottom to see the size of virus vs bacteria vs other potential contaminates and magnify to greater levels. Black Berkey purification elements have been tested to remove both pathogenic bacteria and viruses to greater than the EPA purification standards.

    This suggests that larger bacteria, such as cyanobacteria, should also be effectively removed. Without test data on that specific microbe however, NMCL does not make that specific claim. The MS-2 virus is 24-26 nm in size. The Fr Coliphage virus is 25nm in size. In other words, they are over 1,000 times smaller than  Cyanobateria. Additionally Microcystins, which are the chemical contaminates resulting from cyanobacteria are an organic chemical. Testing of Black Berkey elements has demonstrated they are extremely efficient at removing organic chemicals.

    The EPA defines Microcystins as: “…toxins produced by cyanobacteria. Cyanobacteria are also known as blue-green algae and are ubiquitous in surface water when conditions are favorable for growth and formation of algal blooms. Cyanobacteria release toxins upon cell death or lysis. When released, toxins may persist for weeks to months. Toxins of most concern are microcystins. Microcystins take their name from the
    genera Microcystis. Most microcystins are hepatotoxins (liver toxins). Hepatotoxins are produced by species of the genera Microcystis, Anabena, Nodularia, Oscillatoria among others. Most microcystins are associated with Microcystis aeruginosa. While the liver is the primary target of microcystins, it is also a skin, eye and throat irritant…”


    Further, the EPA states that: “…The following processes are considered effective for the removal/oxidation of microcystin:…. powdered activated carbon (up to 100% for some microcystins but less so for others), granular activated carbon (time-dependent from 100% near start up to 38 to 73% at 3.5 months…”


    Finally, the EPA states that: “…Removal of total microcystins, M-LR, and M-LA, in water by granular activated carbon (GAC) can be very effective where the effectiveness is based on the empty bed contact time, the carbon's age, and possible biodegradation of the toxin. Time-dependent monitoring in a full-scale plant ranged 43 to 60 percent removal for M-LR. Time-dependent monitoring in pilot-scale studies ranged from greater than 99 percent at one month to 73 percent at 3.5 months for M-LR, and from greater than 99 percent at one month to 38 percent at 3.5 months for M-LA…”


    Based upon the above Internet research, Black Berkey element microbe and organic chemical removal test data and the information provided by the EPA in their reference material cited above; these all suggest that Berkey water purification systems should be extremely effective at removing and reducing contaminates resulting from the current algae bloom. NMCL also highly recommends that whenever possible, the cleanest source water available should always be utilized.

  • Corroded Underground Gas Tanks Pose Water Contamination Threat

    Lab tests have shown that underground gas tanks at over 150,000 US gas stations pose a potential water contamination hazard. Many of the underground gas tanks have corroded parts that could lead to failure or leaks that may contaminate groundwater, from where much of US drinking water supplies originate. Field inspections conducted across 9 states have revealed that key components of gas storage tanks, such as sump-pumps, are commonly corroded. In most of the reported cases the corroded tanks stored a mixture of gasoline-ethanol fuels, together with the existence of Acetobacter aceti -- a strain of bacteria that is able to convert ethanol to acetic acid, a highly corrosive agent.

    gas tank

    Upon conducting a follow up laboratory study, the National Institute of Standards and Technology (NIST) found that corrosion of steel alloy components was severe when exposed to the combination of ethanol and vaporized acetic acid, often eating 1mm of steel per annum. Considering these findings, researchers from the NIST recommend that gas stations should consider replacing casings of submersible pumps constructed from cast iron or steel at much shorter intervals. However, at a cost of anywhere between $1500 - $2500 per storage tank, these retrofits could be costly, especially tanking into account that there are over 500,000 underground gas storage tanks dotted around the US.

    The NIST assessment only looked at components of sump-pumps, which are found immediately below tank access covers and thus were readily accessible. The sump-pumps pump fuel from the gas storage tanks below, to the gas pumps at filling stations. While only the sump-pumps were tested, researchers are concerned that pipes, and even the gas storage tanks themselves, could be constructed from steel, which would make them vulnerable to corrosion too.

    "We know there are corrosion issues associated with the inside of some tanks. We're not sure, at this point, if that type of corrosion is caused by the bacteria," says NIST co-author, Jeffrey Sowards.

    Most of the gas storage facilities across the US were designed to contain unblended gasoline. Now, ethanol, a fuel derived from corn, is being widely used as a fuel additive due to the benefits it offers. An earlier NIST study showed that pipeline cracking was accelerated when ethanol-loving bacteria were present.

    For their latest study, the NIST research team studied the effect on samples made of steel and copper alloys exposed to conditions similar to those found at sump-pumps -- samples were either placed in a solution of ethanol and water to which bacteria was added, or exposed to vapors above this mixture. They then measured the rate of corrosion over a 30-day period. Their results echoed the findings reported by field inspectors.

    Steel components exposed to vapors experienced the most damage, with copper components experiencing some damage, albeit slower, both when immersed in the fuel and when exposed to vapors. Immersed steel corroded slowly, which the authors suggest may be attributed to a protective biofilm coating produced by the bacteria.

    Even though corrosion on copper was slow and could take approximately 15 years for holes to form in copper tube with a wall thickness of 1.2mm, the researchers observed localized corrosion on cold-worked copper, as used in tubing for sump-pumps. Consequently, stress-corrosion cracking is an area of concern where copper tubing is bent, as it would substantially reduce the lifetime of the tube and lead to leaks.

    Journal Reference:

    J.W. Sowards and E. Mansfield. Corrosion of copper and steel alloys in a simulated underground storage tank sump environment containing acid producing bacteria. Corrosion Science. July, 2014. In press, corrected proof available online. DOI: 10.1016/j.corsci.2014.07.009.

  • Groundwater is Rapidly Being Depleted in the Parched West

    A recent study conducted by NASA scientists in collaboration with researchers from the University of California, Irvine has found that more than 75% of the water lost in the parched Colorado River Basin originated from groundwater resources. The researchers are concerned that the loss of such a large percentage of the groundwater resources could pose a far graver threat to water supplies in the western states than initially thought.

    water canyon

    This study, which was recently published online in the journal Geophysical Research Letters, is the first scientific study to quantify the contribution of groundwater in satisfying the water requirements of the western USA. The Colorado River Basin has been severely water-stressed for a prolonged period, having suffered the driest 14 year spell over the past hundred years.

    Using data gathered by NASA's Gravity Recovery and Climate Experiment (GRACE) satellite project, the scientists recorded monthly changes in water volume of both surface-water and groundwater resources. Data recorded between 2004 to 2013 have shown that the approximately 65km3 of freshwater reserves equates to nearly twice the capacity of the largest freshwater reservoir in the US -- Lake Mead in Nevada. More than 75% of this total (50 km3) has been attributed to loss of groundwater.

    "We don't know exactly how much groundwater we have left, so we don't know when we're going to run out," said Stephanie Castle, a water resources specialist at the University of California, Irvine, and the study's lead author. "This is a lot of water to lose. We thought that the picture could be pretty bad, but this was shocking."

    The US Bureau of Reclamation is responsible for managing surface water resources in the Colorado River Basin, and this management body records these water losses. However, water extraction from underground sources is controlled by individual states, and in many cases losses are rarely if ever recorded.

    According to Jay Famiglietti, a senior water cycle scientist at JPL and senior author of the study, satellites provide the only solution for observations of such a wide scale, as is the case in this study. GRACE acts like a massive airborne scale that is able to measure changes in mass in the land below. Fluctuations in water levels affect the strength of local gravitational forces, so by regularly recording these gravitational measurements GRACE provides information on regional water fluctuations over any given period.

    As the single major river supplying water to the 40 million residents and 4 million acres of agricultural land across 7 states in the southwest, the Colorado River is essential for the survival of millions of people -- both for drinking water and for food.

    Considering that water levels in Lake Mead are currently at record low levels, the research team wanted to assess whether the Colorado River Basin, lake many other regions across the world, is relying on its underground reserves to supplement the surface-water shortfalls. This study shows that there is indeed a strong and long-term dependence on groundwater to meet the shortfall between water supply and water demand.

    According to Famiglietti, this rapid rate of water depletion will exacerbate the water woes of the nation by further reducing the rate of stream flow of the Colorado River. "Combined with declining snowpack and population growth, this will likely threaten the long-term ability of the basin to meet its water allocation commitments to the seven basin states and to Mexico," Famiglietti notes.

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