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  • Clean Air = Clean Water - Clean Air Act credited for improving Chesapeake Bay Water Quality

    The saying, 'what goes up must come down,' certainly holds some weight (no pun intended), but now appears to influence water quality too.

    A recent study shows that cleaner air above the Potomac watershed, including that of the Washington DC metropole may account for the recent improvements in Chesapeake Bay water quality. A team of researchers from the University of Maryland Center for Environmental Science suggest that there is a link between improved water quality of freshwater systems in the Upper Potomac River Basin and improved air quality as a result of the Clean Air Act, which has seen a reduction in nitrogen pollution contaminating land and freshwater systems in the Potomac watershed.


    According to lead author, Keith Eshleman, a professor at the University of Maryland Center for Environmental Science:

    "The recent water quality successes in the Chesapeake Bay restoration are apparently driven more by air quality regulation rather than by water quality control efforts. These air quality regulations were intended to address human health issues and acid sensitive streams. No one thought you would have this positive impact on water quality. It was totally unanticipated."

    Chesapeake Bay is the largest estuary in the US. It is also one of the most polluted, suffering from high nutrient loads and hypoxic conditions due to oxygen depletion resulting from excessive nitrogen inputs. Much focus, and credit, has been given to improved land-based strategies, such as wastewater treatment and agricultural practices, to reduce nitrogen pollution in freshwater systems. Yet the research team found that the improvement in water quality in the Upper Potomac River Basin, covering an area of approximate 12,000 miles that extends across the District of Columbia, Pennsylvania, Virginia, West Virginia and Maryland, can be attributed to improved air quality, or more specifically, due to a reduction in atmospheric nitrogen deposits which have been curbed as a result of the Clean Air Act, introduced in 1973 and amended in 1990.

    "Most best management practices--like a riparian buffer or retention pond--only impact a relatively small area," said Eshleman. "You can think about the Clean Air Act as a best management practice that affects every square meter of the watershed."

    Nitrogen in the atmosphere — largely arising from emissions produced when fossil fuels are burnt — is eventually deposited on land or on surface waters. If the amount of nitrogen that is deposited is higher than the amount of nitrogen that plants and trees need for growth, soils may become nitrogen saturated. This surplus nitrogen can enter freshwater systems, where it can result in algal blooms that negatively impact aquatic life in freshwater and marine ecosystems.

    The scientists have been analyzing water quality data from streams and rivers in the Upper Potomac River Basin since 1986. They have discovered that water quality throughout the watershed has improved universally. In particular, the scientists noted a decline in atmospheric nitrogen deposition since 1996 — the same period that emission limits were placed on coal-fired boilers. The researchers also noted that nitrate concentrations in the Upper Potomac river began to decline soon thereafter, and continued to do so through to 2012. As a result, nitrogen saturation within the watershed was quickly reversed. The study suggests that in the future, water quality within the Potomac watershed is likely to improve further as cleaner energy sources such as renewables and natural gas replace coal-fired energy plants.

    Journal Reference

    Keith N. Eshleman, Robert D. Sabo. Declining nitrate-N yields in the Upper Potomac River Basin: What is really driving progress under the Chesapeake Bay restoration? Atmospheric Environment, 2016; DOI: 10.1016/j.atmosenv.2016.07.004

  • Drinking Water to Control Weight

    When you're feeling peckish and have the urge to snack on junk food, rather have a glass of water instead. Not only will this keep you hydrated, it helps your muscles to work more efficiently, and will also stave away those hunger pangs to help you keep your weight under control.

    In a recent study involving 10,000 adults, ranging in age from 18 to 64, researchers show that drinking lots of water, together with eating fruit and veggies with a high water content, not only keeps our bodies hydrated but can assist with weight control, especially for those of us who are overweight and can afford to lose a few pounds.

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    According to Dr Tammy Chang, an assistant professor in the department of family medicine at the University of Michigan Medical School, and lead author of the study: "Staying hydrated is good for you no matter what, and our study suggests it may also be linked to maintaining a healthy weight. Our findings suggest that hydration may deserve more attention when thinking about addressing obesity on a population level."

    Dehydration can affect our physical, emotional and mental well being, causing headaches, kidney problems and constipation, as well as negatively impacting our moods, memory and ability to pay attention.

    But, according to Chang, the amount of water consumed is not necessarily a clear indicator of hydration, as the amount of water needed to keep hydrated varies from person to person and is affected by factors such as body size, activity levels and the climate where we live and work.
    "Imagine if you were a landscaper in Arizona versus a receptionist in Michigan," explains Chang. "The amount of water it takes to stay hydrated will be drastically different."

    For this study, the researchers looked at hydration from a new angle — it's not so much the volume of water that you drink, but how hydrated your body becomes after doing so. In order to assess that, they analyzed urine samples of study participants to measure water concentrations.

    When we are hydrated our heart is able to pump blood to our muscles more efficiently, which in turn enables them to work more efficiently. The research team found that keeping hydrated was particularly important for those of us with a body mass index (BMI) score higher than 25, which is considered overweight. According to the US Department of Health & Human Services, two thirds of the American population fall on this end of the BMI scale, which in effect means that many of us could benefit from being better hydrated.

    "We found hydration and BMI/obesity are associated. A bigger person needs more water than a smaller person to stay hydrated," said Chang. "It could be that those people with higher BMI are more likely to be inadequately hydrated or that those that stay well hydrated are less likely to be obese."

    In another study, researchers tested how drinking water before a meal affects the stomach and brain to influence feelings of satiety. They found that participants who drank more water felt less hungry before eating the meal, and fuller afterwards.

    Drinking water has obvious health benefits, and it appears that it can help with weight control too. However, bear in mind that water can also contain contaminants that can be harmful to our health. The best option is to drink lots of purified water. For optimal health, invest in a good quality drinking water filter that can remove a wide range of harmful water pollutants to provide you with a source of pure healthy drinking water to keep your body hydrated.

    Journal Reference

    Chang et al. Inadequate Hydration, BMI, and Obesity Among US Adults: NHANES 2009–2012. Ann Fam Med July/August 2016 vol. 14 no. 4 320-324. doi: 10.1370/afm.1951

  • Water-efficient Crop Production

    The problem of how to boost food production is an important issue for humanity, considering our limited water resources and the ever-growing global population. Water usage at its current level is already unsustainable, with around 70% of global water usage being used for agriculture.

    Water extraction for crop growth not only lowers the groundwater table, exacerbating water scarcity, it also significantly adds to the volume of water moving from land to sea — estimated to be around 50 net cubic miles.  This is equivalent to three times the volume of water that cascades down the Niagara Falls every year — making a 30% contribution to sea level rise. According to the Global Agriculture Report, water demand for irrigation has increased three-fold over the last 50 years, and is expected to rise by another 20% by 2050.


    Approximately 80% of water that is released into the atmosphere from terrestrial sources does so via transpiration in plants, who take up the water from soils via their roots and then release it via their leaves during the process of photosynthesis. Considering that so much water is lost via plant leaves during production, it is the greatest factor limiting the expansion of crop production globally. Consequently, if we wish to reduce the amount of water used in agriculture while still maintaining food security in the years ahead, it is essential that we find crop plants that utilize water more efficiently.

    Now researchers from the Technical University of Munich (TUM) have done just that. By identifying and permanently activating the natural water-conservation mechanism used by plants when water is scarce, which allows them to absorb carbon dioxide with limited water loss, the scientists have managed to get the plants to make more efficient use of water without negatively affecting their growth.

    Gaseous Exchange in Plants

    Plants regulate the flow of carbon dioxide and water vapor through the stomata — tiny pores found on the surface of plant leaves. When these pores close, water loss is reduced; however, it also limits the absorption of carbon dioxide. When the stomata are open to allow carbon dioxide to enter, they can lose between 500-1000 molecules of water, depending on the humidity and air temperature. However, during dry periods when water is not so readily available plants are able to reduce internal carbon dioxide concentrations in order to absorb carbon dioxide more effectively.

    "Plants have the ability to cut water loss during CO2 absorption in half, but they will only switch to this water-saving mode when water is in short supply," says Erwin Grill, Professor of Botany at TUM. "With arable crops, plants with a perpetually activated water-saving strategy would preserve the moisture in the ground to use it for growth and survival at a later point in times of drought."

    Water-saving Mode Activated by Plant Hormone

    The researchers have discovered that this water-saving mode is activated by the plant hormone known as abscisic acid, which plants produce at higher quantities when water is scarce. Tests conducted on mouse-ear cress (Arabidopsis), which has fourteen receptors dedicated to detecting this hormone signal, show that when production of these receptors is increased, plants will switch to water-saving mode, regardless of whether water is scarce or not. However, of these fourteen receptors, only three did not have a negative effect on plant growth, but a 40% water saving is feasible without negatively impacting the plant's overall performance.
    While initial laboratory experiments conducted in a phytochamber simulating field conditions show positive results, the next step would be to determine whether the same water-saving effects can be achieved in the field.

    "It remains to be seen if crop plants such as wheat, corn, and rice can produce more biomass with the same amount of water using this mechanism," says Professor Grill. "We are optimistic"

    Since the mechanisms involved are present in all plants, it should be possible to transfer these results from the model plant Arabidopsis to crop plants. This would be an important step towards ensuring future food security.

    Journal Reference

    Zhenyu Yang, Jinghui Liu, Stefanie V. Tischer, Alexander Christmann, Wilhelm Windisch, Hans Schnyder, and Erwin Grill: Leveraging abscisic acid receptors for efficient water use in Arabidopsis, PNAS 2016. DOI: 10.1073/pnas.1601954113
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  • Drinking Water of 6 Million US Citizens Contaminated with Toxic Chemicals

    Unsafe levels of toxic chemicals widely used in industry have been found in drinking water supplies serving six million Americans.

    A recent study conducted by Harvard scientists, published in the scientific journal Environmental Science & Technology Letters, has revealed that fluorinated compounds — perfluoroalkyl and polyfluoroalkyl (PFASs) — industrial chemicals that pose a health risk, including an increased risk of cancer, occur at elevated levels in public drinking water systems across the country.

    "For many years, chemicals with unknown toxicities, such as PFASs, were allowed to be used and released to the environment, and we now have to face the severe consequences," said lead author Xindi Hu, a doctoral student in the Department of Environmental Health at Harvard Chan School and Environmental Science and Engineering at SEAS. "In addition, the actual number of people exposed may be even higher than our study found, because government data for levels of these compounds in drinking water is lacking for almost a third of the U.S. population--about 100 million people."

    PFAS compounds have been widely used in both commercial and industrial products, including fire-fighting foam and everyday products such as clothing, food wrappers and pots and pans. Some of the health risks associated with PFASs include hormone disruption, obesity, high cholesterol and cancer. Yet while some manufacturers have opted to discontinue their use due to the safety risks they pose, these carcinogenic chemicals are still found in wildlife and people, with drinking water being a key source of exposure.


    For the study, the research team analyzed water quality data collected by the EPA between 2013 to 2015 for public water supplies across the country to determine the concentrations of PFASs — in total, over 36,000 water samples were assessed. They also examined industrial sites where PFASs are manufactured; sites where fire-fighting training is conducted or where fire extinguishing foam is routinely used, such as military training sites and airports; as well as wastewater treatment facilities where discharged water could potentially contaminate groundwater, as standard wastewater treatment methods are not able to remove PFASs during the treatment process. Wastewater sludge used on crops as fertilizer could also present another source of groundwater contamination by PFASs.

    The study revealed that in 194 of the 4,864 water supplies tested, PFAS toxins occurred at concentrations equal to or greater than the EPA's minimum reporting level requirements, with drinking water supplies from 13 states representing 75% of the observations, including drinking water from the following states (listed in order of frequency of occurence): California, New Jersey, North Carolina, Alabama, Florida, Pennsylvania, Ohio, New York, Georgia, Minnesota, Arizona, Massachusetts, and Illinois.

    According to the study, 66 of the public water supply systems examined, providing drinking water to six million Americans, contained at least one water sample that exhibited PFASs at levels equal to or higher than the EPA safety standard of 70 parts per trillion (ng/L) for two types of PFASs, perfluorooctanoic acid and perfluorooctanesulfonic acid, with concentrations as high as 349 ng/L for the former being observed in Warminster, PA, and 1,800 ng/L for the latter being observed in Newark, DE.

    Watersheds situated close to wastewater treatment facilities, military bases, and industrial sites — all sites where these compounds are typically found — had the highest concentrations of PFASs.

    According to co-author, Elsie Sunderland, an associate professor at Harvard, these chemicals are 'potent immunotoxicants in children' with recent studies suggesting that their safety standards for drinking water should be at levels much lower than those currently set by the EPA.

    Health Implications of Exposure to PFASs

    In another Harvard study led by Philippe Grandjean, a co-author of this paper, the health implications of exposure to PFASs are discussed. The study, which was recently published in Environmental Health Perspectives, suggests that exposure to PFASs in early childhood can impair immune functioning and reduce the efficacy of vaccinating children against diseases such as tetanus and diphtheria.

    PFAS's fall under the category of PFC's - Perfluorinated Chemicals. PFOA, PFOS, etc.  The Black Berkey elements that come standard with our Berkey systems do reduce these contaminates, to an Extreme Degree (in parts per trillion). Berkey water filter PFOA test results can be found here.

    Journal References

    Xindi C. Hu, David Q. Andrews, Andrew B. Lindstrom, Thomas A. Bruton, Laurel A. Schaider, Philippe Grandjean, Rainer Lohmann, Courtney C. Carignan, Arlene Blum, Simona A. Balan, Christopher P. Higgins, and Elsie M. Sunderland. Detection of Poly- and Perfluoroalkyl Substances (PFASs) in U.S. Drinking Water Linked to Industrial Sites, Military Fire Training Areas, and Wastewater Treatment Plants. Environmental Science & Technology Letters, online August 9, 2016, doi: 10.1021/acs.estlett.6b00260

    Philippe Grandjean, Carsten Heilmann, Pal Weihe, Flemming Nielsen, Ulla B. Mogensen, and Esben Budtz-Jørgensen. Serum Vaccine Antibody Concentrations in Adolescents Exposed to Perfluorinated Compounds. Environmental Health Perspectives, online August 9, 2016, doi: 10.1289/EHP275

  • Using Sound to Echolocate Underground Water Leaks

    Researchers from Concordia University have developed a method of locating underground in distribution networks with a 99.5% accuracy.

    Water scarcity is a worldwide problem that will challenge 33% of the global population by 2025. This water crisis can be averted if one of the main culprits — leaks — can be addressed. It is estimated that between 20-30% of water leaving water treatment plants is lost as a result of water leakage, which can be resolved if the problem is addressed and fixed.

    water-pipe-880975_960_720 (1)

    But first we have to find the leaks, which can be difficult to detect when pipes are buried underground. When repair work is undertaken, this needs to be done as precisely as possible, to not only limit the cost involved with excavation work and resurfacing, but also to limit disruptions to traffic, commuter frustration, and loss of income due to disruptions to local trade and industry.

    Furthermore, leaking pipes not only waste valuable water; damaged water pipes allow pollutants to enter the water flowing through them via the holes in the pipelines, posing a drinking water hazard and health risk to consumers.

    Thankfully, scientists from Concordia University, Montreal, have developed an innovative tool — known as a noise logger — to address this problem. They recently conducted a study to test the effectiveness of the tool, traveling to Doha in the water scarce nation of Qatar to apply the noise logger in detecting water leaks within Qatar University's water network.
    Qatar not only has one of the lowest rainfall rates globally, but also among the highest evaporation rates globally. Consequently, when rain does fall it quickly evaporates back into the atmosphere in the form of water vapor.

    According to co-author, Tarek Zayed, a professor in the Department of Building, Civil and Environmental Engineering at Concordia University: "Qatar is currently facing significant challenges regarding its water supply. Its water distribution network currently suffers from 30-35% water loss due to leakage."

    The results of the study, which where recently published in the Journal of Infrustructure, show that the noise logger is not only effective at detecting leaks, but can do so with fine accuracy before any major earthworks are required.

    "This approach can reduce the duration of a leak, as well as the cost and time involved in locating the site in need of repair." " explains Zayed

    To test their theory, the researchers installed noise loggers on Qatar University's water mains network to record sounds generated by water leaks over a 2-hour period. They then scrutinized the sound readings, comparing noise level and spread. The researchers deemed a leak investigation necessary when a consistent sound anomaly was detected.

    After monitoring Qatar University's water mains for several weeks they collected sound readings from 140 points across the water network. They then used mathematical model simulations to pin-point the exact location of where water leaks were occurring. After investigating the locations of the leaks, Qatar University's facilities management reported that the researchers had detected the leaks with 99.5% accuracy.

    The researchers now plan to conduct surveys of leak data from real-life municipal water networks where noise loggers are used in an effort to develop tailor-made leak location prediction models.

    Journal Reference
    El-Abbasy, M., Mosleh, F., Senouci, A., Zayed, T., and Al-Derham, H. (2016). "Locating Leaks in Water Mains Using Noise Loggers." J. Infrastruct. Syst. , 10.1061/(ASCE)IS.1943-555X.0000305 , 04016012.

  • 5300 US Water Systems Found to be Tainted by Lead

    According to a recent CNN report, 5,300 US water systems are tainted with lead, exposing approximately 18 million Americans to dangerously high levels of lead.

    This report, which was prepared by the Natural Resources Defense Council (NRDC), states the US Environmental Protection Agency (EPA) is aware of the problem, but has not taken much action to prevent the danger this poses to consumers.

    "Imagine a cop sitting, watching people run stop signs, and speed at 90 miles per hour in small communities and still doing absolutely nothing about it -- knowing the people who are violating the law. And doing nothing. That's unfortunately what we have now," said Erik Olson, health program director at Natural Resources Defense Council, which analyzed the EPA's data for its report.

    In this scenario, the 'cop' is the states where there are concerns — who have a duty to ensure that the water they provide residents is safe to drink — together with the EPA, the water watchdog agency, who is supposed to act when water standards are not met. Yet in many instances the EPA has been failing to step in.

    The EPA implemented a lead and copper regulation to protect American's from the country's aging water infrastructure. Yet, in many cases the safeguards put in place are not being met. According to the CNN report, more than 5,300 US water systems do not comply with the safety measures set out in the ruling, putting residents at the same risk as those living in Flint, Michigan. The affected water utilities are guilty of several violations including:

    • Failure to adequately test for lead
    • Failure to adequately treat water to prevent lead contamination
    • Failure to inform residents of lead contamination

    According to the report, in 817 instances, states stepped in and took action, while the EPA only intervened in just 88 instances. To make matters worse, the report has revealed that in many cases the EPA is aware that many water utilities buck the system by using dubious testing methods to avoid detecting high concentrations of lead, such as getting residents to flush their pipes before testing. Yet they have not stepped in to take action, choosing rather to turn a blind eye, even though this puts residents at risk of lead poisoning. Consequently, the number of water systems — which could number hundreds, or even thousands — and ultimately the number of Americans affected, could be much, much higher. What is even more concerning is that the public is blissfully unaware of the hazards they face.

    These violations are not restricted to small towns like Flint; they effect large cities servicing thousands of residents. Philadelphia is a key example. Of the approximately 50,000 residences served by lead water pipes, the city tested a mere 40 homes for lead, mostly from homes considered low risk. Seven of the homes tested had high levels of lead. The residents in the remaining 49,960 homes that were not tested have no idea whether they are being exposed to high levels of lead or not.

    The NRDC report implies that these results are skewed and thus flawed. Yanna Lambrinidou, a water researcher at Virgina Tech who has been monitoring the situation, says the EPA should immediately alert Philadelphia residents that the test results are unreliable, so that people can take precautions to ensure they are not exposed to high levels of lead.

    In the meantime, the EPA and the state of Pennsylvania are throwing the ball around with the EPA saying that the state is responsible for enforcing the lead rule in Philadelphia, while the Philadelphia Mayor's office saying that it plans to adhere to the EPA's new guidelines the next time it tests for lead, which will be in 2017. In the meantime, there is an entire city — 50,000 homes — that are not protected. Philadelphia, like Flint, is just the tip of the iceberg. Other cities are affected too. Approximately 97% of violations related to lead that the EPA has taken note of are for failure to adequately monitor lead levels in drinking water.

    "I think that the basic problem is that the federal EPA and the water officials, and a lot of communities across the country are very tight. And the EPA has been very reluctant to take enforcement action against them in most cases. They're friends, they hang out with each other, they ask for each other's advice, and you get close after a while," Olson said.

    While lead is not safe at any level, the EPA standard for drinking water was set at 15 parts per billion (ppb) in 1990. When lead levels exceed this standard, regulators are supposed to take action, forcing water utilities to take measures to correct and address the problem to ensure water is safe to drink.

    While Flint has made the headlines recently due to the extremely high levels of lead recorded (over 10,000 ppb in some cases), the NRDC has revealed that a water system in Utah serving 1,675 residents had lead levels of 6,000 ppb. In addition, "there are eight water systems in seven different states and territories with lead levels above 1,000 ppb; and 25 water systems with lead levels above 200 ppb."

    Further Info:

    For more information, including maps showing which communities are affected, read the full CNN report.

    How to test for lead in your home water supply

  • More Efficient Farming Methods Improve River Water Quality

    The Illinois River has seen an improvement in water quality due to the reduction of a key pollutant: nitrates. A recent study conducted by researchers from the University of Illinois College of Agricultural, Consumer and Environmental Sciences has found that nitrate levels in the Illinois River between 2010-2014 were 10% less than average nitrate levels recorded between 1980 an the early 1990s.


    The US Environmental Protection Agency (EPA) ultimately is striving to reduce the levels of nitrates and phosphorus by 45% in the Mississippi River, which will in turn help reduce the extent of the 'dead zone' — a seasonally hypoxic area — that forms in the Gulf of Mexico as a result of high nitrate loads that flow from tributaries such as the Illinois River into the Mississippi River and then into the Gulf. The state of Illinois together with other states across the Mid-west have implemented strategies to reduce these nitrate loads in an effort to limit the impact on inshore coastal waters.

    "The recent reduction in nitrate load in the Illinois River is a promising sign," says the study's lead author, Greg McIsaac, a researcher at the University of Illinois, who notes that the study concluded before nitrate records for 2015 were made available. "Now that these data are available, we know that the Illinois River nitrate load from 2011 to 2015 was 15% lower than the load measured in the baseline period from 1980 to 1996. This 15% reduction is a milestone that the state hoped to achieve for all its rivers by 2025," he says.

    Besides assessing nitrate level trends in the Illinois River between 1976-2014, the researchers also tried to pin-point the causes of any changes in nitrate loads and/or concentrations. They looked at nitrate levels in treated wastewater that was discharged into the Illinois River by water treatment facilities in the Greater Chicago area between 1983-2014, as well as annual agricultural records, such as fertilizer sales, crop yields and livestock numbers to determine agricultural nitrogen residues in soil for each year — or the amount of nitrogen that is available to plants in the form of manure, fertilizer, or by biological fixation, yet not taken up by plants or harvested with the grain. A large portion of these nitrogen residues remain in soils as nitrates, which can wash into rivers through runoff or by leaching through soils into groundwater.
    According to co-author, Mark David, a biogeochemist at the University of Illinois, the highest levels of residual agricultural nitrogen were recorded in the late 1980s, after a period of extensive drought which saw poor corn yields.

    "Beginning around 1990, the residual agricultural nitrogen began to decline, most likely due to improved fertilizer management and higher corn yields. Since 1980, the amount of nitrogen fertilizer sold in the watershed remained relatively constant, but corn yields increased by about 50%," says David. "This means that more of the nitrogen fertilizer applied was taken up by the corn and harvested in the grain and less was left in the soil or washed down the river."

    After analyzing the nitrate data, the researchers determined that yearly nitrate loads correlated with the rate of river flow, as well as nitrate discharges from Chicago's wastewater treatment works and agricultural nitrogen residues. Similarly, nitrate concentrations were correlated with agricultural nitrogen residues and nitrates in Chicago wastewater discharges, however, they did not correlate with river flow rates.

    Precipitation together with the rate of river flow have a strong influence on nitrate loads in rivers, yet both tend to be considerably erratic. According to McIsaac, considering that the 5-year average river flow rate for the period 2007-2011 was the highest on record since measurements began in 1939, it is encouraging that nitrate loads have recently declined despite river flow rates being higher than normal.

    In terms of nitrate concentrations, we have seen a more consistent decline since around 1990, when high concentrations were the norm. According to McIsaac, the disparity between nitrate loads and nitrate concentrations can be attributed to the fact that nitrate load is affected by both nitrate concentrations and river flow rates — with precipitation having a strong influence over the latter. Nitrate concentrations, on the other hand, are not. Stronger flow rates enable the river to carry greater loads of nitrates, yet the nitrate concentrations do not necessarily change.

    What is the outlook for the future? According to the authors, there are a number of factors that will determine whether nitrate loads and concentrations will continue to drop in the years ahead.

    "If the annual river flows return to their 1976-2005 average values, and if nitrogen fertilizer efficiency remains high or continues to improve, there likely will be a decline in nitrate loads in the Illinois River," David explains. "On the other hand, if river flows remain high, which may be a consequence of climate change, meeting the nitrate reduction goals will likely require more conservation effort than originally proposed."

    Journal Reference

    Gregory F. McIsaac, Mark B. David, and George Z. Gertner. Illinois River

    nitrate-nitrogen concentrations and loads: Long-term variation and association with watershed nitrogen inputs. Journal of Environmental Quality. 6 May, 2016.

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  • Coal Ash Ponds Leak Long-lasting Toxic Substances

    A recent study of unlined coal ash ponds sited near twenty-one power stations across five south eastern states in the US has found that they leak toxins that consistently contaminate nearby groundwater and surface freshwater systems with long-lasting effects.

    Researchers from Duke University found high concentrations of heavy metal contaminants, including selenium and arsenic, in freshwater samples taken from all the test sites. In 29% of the water samples concentrations of toxic trace elements were above the EPA safety standards set for both ecological health and drinking water.

    "In all the investigated sites, we saw evidence of leaking," said co-author, Avner Vengosh, a professor of geochemistry and water quality in Duke University's Nicholas School of the Environment. "Some of the impacted water had high levels of contaminants.

    The results of the study, which was recently published online in Environmental Science & Technology, do not include drinking water wells; however, according to Vengosh, these will be assessed in a follow-on study.

    coal ash

    During 2015 the research team analyzed water samples taken from 39 surface water bodies together with coal ash pond seep samples from 7 different sites. In addition, they examined state records of  water quality data recorded at 156 shallow wells dug to monitor groundwater quality adjacent to coal ash ponds at 14 power plants in North Carolina.

    While shallow groundwater monitoring wells are generally only 30-50 feet deep and do not reach the same depth as most drinking water wells, which tend to be between 100-300 feet deep, according to Vengosh, these contaminants can still potentially leach to greater depths and contaminate drinking water wells.

    The study shows that this contamination is not only widespread, but also the toxins tend to persist in the environment for a very long time. Many of the study sites are no longer in use and coal ash is no longer dumped there, yet surface water bodies, and even groundwater in one case, showed evidence of contamination.

    "The degree to which leakage affects the concentration of toxins in nearby waters varies because of several factors, including the nature of the coal ash, processes in the pond and the flow through the local soil," said Jennie Harkness, a doctoral student at the Nicholas School and the lead author of the study.

    While in certain cases coal ash ponds may legally release liquid effluent into surrounding surface water systems via regulated outlets, the data from this study show that effluent is also being released in ways that are not permitted, posing a threat to both aquatic ecosystems and drinking water resources.

    The site with the highest levels of heavy metal contaminants present in shallow groundwater wells was located adjacent to a Tennessee ash disposal site that is no longer in use. Water samples showed that levels of iron, lead, zinc, cadmium, selenium and nickel exceeded safety standards set for drinking water quality and health of aquatic life. According to Vengosh, the study's findings show that even if these coal ash ponds were removed we would still be left with a legacy of groundwater contamination as a result of decades of leaking, which would require a mammoth effort to address.

    Journal Reference

    Jennifer Harkness, Barry Sulkin and Avner Vengosh.  Evidence for Coal Ash Ponds Leaking in Southeastern United States. Environmental Science and Technology, (online June 10, 2016). DOI: 10.1021/acs.est.6b017276

  • Aquatic Food Chains Threatened by Hydropower Hydropeaking

    Aquatic insect populations have declined in many rivers downstream from hydroelectric dams, threatening fish and other wildlife that depend on them for survival. Now researchers from the US Geological Survey (USGS) together with collaborators from Oregon-, Utah- and Idaho State Universities, have found that hydropeaking — a practice widely used in the management of hydroelectric dams that involves increasing river flow rates during the daytime when demand for electricity is high — is likely the cause. Their findings suggest that these negative impacts could be mitigated if alternative hydropower methods were used.

    Aquatic insects form a vital part of food webs in freshwater ecosystems and provide the primary source of food for many different species, including fish, reptiles, bats and birds, as well as other wildlife. The study, which was recently published online in the scientific journal BioScience, assessed the impact that sudden changes in water levels have on aquatic insects at all stages of their lifecycle, and provides the foundation for determining how to improve the health of rivers downstream from hydropeaking dams all over the world.

    usgs insects

    The study was partly assisted by data collected in a citizen science project where educational groups, river guides and other citizen scientists collected over 2,500 insect samples from a stretch of Colorado River downstream from the Glen Canyon Dam in the Grand Canyon. The researchers compared insect diversity of 16 large dammed river systems across the western regions of the US that have varying degrees of hydropeaking to assess how the impact of abrupt changes in water levels affected river health.

    "For the first time, this study determines the ecological impacts of hydropeaking separated from other dam-imposed stressors, and identifies the specific cause-and-effect relationships responsible for biodiversity loss below hydroelectric dams," explains lead author Ted Kennedy, a USGS scientist. "These results may help resource managers improve river health while still meeting societal needs for renewable hydroelectricity."

    Hydroelectric power provides approximately 19% of the electricity used globally, and far exceeds that produced by wind, solar or other renewable energy sources combined. Many hydroelectric dams practice hydropeaking, where the volume of water released can vary dramatically within a day, resulting in large hourly shifts in river levels that create artificially induced tides along the shoreline of rivers, which freshwater organisms simply are not adapted to cope with.

    Many insects of ecological importance, such as mayflies, stoneflies and caddisflies, attach their eggs onto a substrate such as aquatic vegetation or rocks that are submerged just beneath the surface of the water, where the eggs soon hatch. But should water levels drop rapidly, exposing the eggs to the sun and air, they can become desiccated causing the larvae to die within the egg before hatching.

    "These large daily rises and peaks in river flows due to hydropower dams are not normal. Prior to the construction of dams, there were almost no major daily changes in river levels in places like the Grand Canyon," said David Lytle, a professor at Oregon State University and co-author of the paper. "This can interrupt the egg-laying practices of some species, and the impact of this was poorly appreciated. Until now, no one really looked at this aspect, and our results show that it causes serious problems for river health."

    For decades, aquatic scientists have been puzzled by the conspicuous absence of stoneflies, mayflies and caddisflies on the Colorado River in the Grand Canyon. This study sheds light on the reason for their absence — the hydropeaking activities of Glen Canyon Dam is partly responsible. The researchers suggest some mitigation measures that dam managers may want to consider, including maintaining low, stable water levels in rivers during times when power demands are low, such as over weekends, to give insects a couple of days to successfully lay (and hatch) their eggs.

    "If mitigation flows are successful, a more diverse community of aquatic insects should improve the health of the Colorado River ecosystem in Grand Canyon, including the largest remaining population of endangered humpback chub," said Kennedy.

    With over 2,500 samples collected by citizen scientists over a 3-year period, this project highlights the important contribution that citizen science makes to research of this nature. The research team partnered with Grand Canyon Youth who provided over 150 samples, to the project — watch them in action here. Having this extensive dataset enabled scientists to reach scientific conclusions which would otherwise have not have been possible.

    "Many urgent questions in ecology remain unanswered, because scientists are bumping up against data limitations where it is impossible for them to collect sufficient data to answer complex questions across large landscapes," notes Kennedy, pointing out that this study highlights the powerful contribution citizen scientists can make to fundamentally advancing knowledge and gaining valuable new scientific insights.

    Journal Reference
    Kennedy TA et al. Flow Management for Hydropower Extirpates Aquatic Insects, Undermining River Food Webs. BioScience (2016) 66(6) doi: 10.1093/biosci/biw059

  • The Dark Side of Anti-Bacterial Soap

    Almost every home in the US uses a variety of household products that contain the anti-bacterial agent triclosan. It is commonly used in the soaps we use for washing our hands or washing our laundry, the toothpaste we use for brushing our teeth, as well as a host of other everyday cleaning products. Consequently, as we go about our daily hygiene or cleaning routine, we are more than likely adding triclosan into our freshwater sources via our wastewater.

    Triclosan is routinely added to toothpaste, antibacterial soaps, household detergents, paints, carpets, and even toys, and while the germ-wary consumer may find some comfort in knowing their family is protected from germs, the reality is that most of these products, especially antibacterial soaps, don't offer much more protection than using normal soap and water.
    Yet triclosan poses a problem — not only does it kill bad bacteria, it also kills beneficial bacteria. Research has shown that triclosan has given rise to antibiotic resistance, making treatment of common ailments and illnesses with antibiotics less effective. Triclosan also poses an environmental risk; it is harmful to algae, and can disrupt normal hormone functioning -- and thus development -- in wildlife. The FDA is busy conducting studies to determine the health risk it poses on humans.

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    While it is believed that the majority of triclosan is removed during the wastewater treatment process, the US Geological Survey (USGS) has found traces of triclosan in approximately 58% of streams tested.

    "What you use has an impact even though you're probably not thinking about it," says Monica Mendez, an associate professor in the Department of Biology and Chemistry at Texas A&M International University, and lead author of a research paper that was recently published in the Journal of Environmental Quality. "If a river happens to be a source of irrigation, could triclosan possibly get into our food?" Mendez asks.

    In order to gain a better understanding of how tricolosan-contaminated water affects soils and plants that are irrigated with it, Mendez and her research team used triclosan-contaminated water to irrigate tomatoes, onions and exposed soil. When the crops were harvested, the researchers detected triclosan in all edible parts of both plants. However, this was at levels considered safe for human consumption.

    The researchers also found that even though triclosan broke down rapidly in soils, it never broke down completely. Instead, it breaks down into other harmful hormone disrupting compounds that can be even more detrimental than triclosan.

    The researchers are also concerned about the effect that triclosan has on bacterial communities living in soils, which are necessary for healthy plant growth. Because triclosan indiscriminately targets both good and bad bacteria, it not only kills disease-causing bacteria, but beneficial bacteria too. Plants tend to flourish in soils that have a thriving and diverse microbial community, but these bacterial communities can be negatively impacted by triclosan.

    "We know that triclosan decreases the diversity of bacterial communities," says Mendez, "But we still need to figure out which good bacteria we are losing."

    This is the first study that measures the effects of long-term, repeated exposure to triclosan on soils and plants. Mendez hopes that future studies will assess the impact that triclosan has on soil microbes.

    "Because we're all concerned about disease-causing bacteria, we generally ignore what happens below ground," Mendez says. "Water and soil come together. We need to look at the quality of both, because food is important."

    Journal Reference
    Monica O. Mendez, Erika M. Valdez, Eileen M. Martinez, Melissa Saucedo, Brittan A. Wilson. Fate of Triclosan in Irrigated Soil: Degradation in Soil and Translocation into Onion and Tomato. Journal of Environment Quality, 2016; 45 (3): 1029 DOI: 10.2134/jeq2015.07.0386

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