Plastics in the Deep Ocean

 

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 Plastic-eating amphipods consume plastics in the deepest ocean waters

A dangerous chemical has tainted N.J. water for decades and the feds are still dragging their feet

by Sol Warren

 

It is a problem that has tainted New Jersey’s drinking water for years.

Areas of the state are contaminated with a cocktail of dangerous, cancer-causing chemicals known as PFAS (per- and polyfluoroalkyl substances) after decades of hazardous disposal by manufacturing plants across New Jersey. Since the 1940s, when use of the chemicals began, PFAS chemicals were discharged in the plants’ wastewater, which then mixed with drinking water supplies. The industrial use of PFAS has been phased out of American facilities in recent years, but the damage has been done.

According to the Centers for Disease Control, the health effects of PFAS exposure range from increased risk of cancer to stunting the growth of children. Exposure to these chemicals, which have been used to manufacture everything from nonstick cook-wear and stain-resistant carpets to cosmetics, is even linked to lower chances of pregnancy in affected women.

But efforts to rectify the issue — particularly on the federal level — have moved slowly.

On Thursday, the U.S. Environmental Protection Agency unveiled its first nationwide “action plan” to deal with the PFAS family of chemicals. The plan includes expanded monitoring of the chemical around the country, continued enforcement actions to cleanup contamination hotspots and further research of the health effects stemming from PFAS consumption.

Yet there are still no federal drinking water standards for the chemicals.

“The PFAS action plan is the most comprehensive cross-agency plan to address an emerging chemical of concern ever undertaken by EPA,” said Andrew Wheeler, the EPA’s Acting Administrator.

The new action plan was announced Thursday morning in Philadelphia, just up the Delaware River from Paulsboro and West Deptford, where New Jerseyans have been grappling with PFAS contamination for years due to the area’s heavily industrial past. It was there that, from 1985 to 2010, Solvay Solexis Specialty Polymers used a member of the PFAS chemical family known as PFNA.

The Solvay plant discharged the chemical within its wastewater and now Gloucester County is home to some of the highest levels of PFNA contamination on Earth. The EPA plan comes months after New Jersey established statewide drinking water standards for PFNA.

PFAS pollution has been found elsewhere in the Garden State, with particularly high concentrations near New Jersey’s military installations like Joint Base McGuire-Dix-Lakehurst and Naval Weapon State Earle, where the use of fire-fighting foam containing the chemicals has dirtied nearby waters.

Wheeler said that the EPA will continue to take enforcement actions against PFAS polluters based on a 2016 health advisory issued by the agency, but drinking water standards under the Safe Drinking Water Act won’t be proposed until the end of the year.

Even after that proposal is unveiled, the rules-making process can take years and is not guaranteed to establish new drinking water standards.

Environmental groups slammed the EPA for not proposing drinking water standards for the chemicals in the new plan.

“While the agency fumbles with this ‘mis-management plan,’ millions of people will be exposed to highly toxic PFAS from drinking contaminated water,” said Erik Olson, the senior director for health and food at the Natural Resources Defense Council. “As a guardian of public health, Administrator Andrew Wheeler should revisit this embarrassing decision.”

Source: NJ.com

 

 

Whole House Water Treatment: Keeping It Simple and Easy

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Simple whole house treatment for city water consists of a sediment filter, a carbon filter, and a TAC scale prevention unit. 

One of the best-kept secrets about water treatment equipment is that to be effective it does not have to be complicated, expensive, and large. The truth is that much of the innovative energy of water treatment professionals in recent years has been directed toward greatly improved performance of traditional items like filter cartridges and toward the development of technologies that provide simpler solutions to problems like scale prevention.

Filter cartridges for city water applications, because of improved efficiency, often outperform large tank-style systems. Similarly, recently developed alternatives to conventional water softeners, like TAC units, can greatly improve water quality and prevent scale buildup without complicated control programming, drain connections, salt purchases, or service agreements.

It is easy to be impressed by the size of a large tank-style whole house carbon filter and to assume that because it is big it works better than a filter that is relatively small. Looks can be deceiving. Compact filter cartridges, made from very tightly packed powdered filter carbon, actually follow a different set of rules than large filters.  Concepts like “empty bed contact time” used to design and to size tank style filters filled with granular carbon do not apply to modern filter cartridges.  In many ways a well- engineered 4.5″ X 20″ carbon block filter cartridge can outperform a carbon tank with several cubic feet of granular carbon.

Here are some advantages of cartridge-style whole house filters as compared with large tank-style backwashing units:

Easy to install. No drain or electrical connection needed. Thus, fewer plumbing connections, no wiring, and greater flexibility in choosing a place to install.

Low purchase price. Typically, a cartridge filter array costs less than 1/2 as much as a tank-style equivalent.

Easy to service. With cartridge units there is little that can go wrong, so an easy cartridge change and an occasional o ring replacement are all that’s needed. Changing a cartridge is a much easier “do it yourself” job than rebedding a tank-style filter.

Versatile. There are many cartridges to choose from.  When you put in a new cartridge, you have a new water filter. If your city changes its disinfectant from chlorine to chloramine, you just change your filter cartridge. If you have a standard-sized filter housing, which is what we recommend, you have literally dozens of cartridges to choose from.

Perhaps the greatest mark of versatility is the ability to easily increase filter capacity by installing two or more carbon filters in parallel, so that each cartridge gets a fraction of the service water.  If your cartridge supports a service flow of six gallons per minute, installing a second in parallel gives you twelve per minute.  The extra carbon unit(s) can be added at the time of the initial installation, or later, to accommodate an increase in family size or other expanded need for filtered water.

 

 

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Two carbon cartridges in parallel double the capacity and greatly reduce pressure drop. The multi-cartridge system provides higher flow rates for larger homes.

For scale prevention, passive TAC systems are becoming a popular substitute for conventional water softeners.  TAC units require no drain connection and no electricity. The only upkeep is an easy media change, recommended for every three years.

The products featured on this page do not require electricity, drain connections, chemicals, or even water for regeneration. There are no electronic controls to program, no manuals to study, no salt to buy, no brine tanks to clean. Annual filter service is so easy most homeowners can do it themselves. Even the media change in the TAC tank (recommended every 3 years) does not require special equipment or great technical know-how.

More information about cartridge-style whole house units and salt-free scale treatment:

Arsenic from abandoned mine


Posted February 27th, 2019

Arsenic, lead in water pouring out of former US mine sites

by Matthew Brown

Associated Press

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Every day many millions of gallons of water loaded with arsenic, lead and other toxic metals flow from some of the most contaminated mining sites in the U.S. and into surrounding streams and ponds without being treated, The Associated Press has found.

That torrent is poisoning aquatic life and tainting drinking water sources in Montana, California, Colorado, Oklahoma and at least five other states.

The pollution is a legacy of how the mining industry was allowed to operate in the U.S. for more than a century. Companies that built mines for silver, lead, gold and other “hardrock” minerals could move on once they were no longer profitable, leaving behind tainted water that still leaks out of the mines or is cleaned up at taxpayer expense.

Using data from public records requests and independent researchers, the AP examined 43 mining sites under federal oversight, some containing dozens or even hundreds of individual mines.

The records show that at average flows, more than 50 million gallons (189 million liters) of contaminated wastewater streams daily from the sites. In many cases, it runs untreated into nearby groundwater, rivers and ponds — a roughly 20-million-gallon (76-million-liter) daily dose of pollution that could fill more than 2,000 tanker trucks.

The remainder of the waste is captured or treated in a costly effort that will need to carry on indefinitely, for perhaps thousands of years, often with little hope for reimbursement.

The volumes vastly exceed the release from Colorado’s Gold King Mine disaster in 2015, when a U.S. Environmental Protection Agency cleanup crew inadvertently triggered the release of 3 million gallons (11.4 million liters) of mustard-colored mine sludge, fouling rivers in three states.

At many mines, the pollution has continued decades after their enlistment in the federal Superfund cleanup program for the nation’s most hazardous sites, which faces sharp cuts under President Donald Trump.

Source: The Oklahoman.

Brine from Desalination


Posted February 25th, 2019

Brine from Desalination Can Be Put to Use

Currently, the world produces more than 100 billion liters (about 27 billion gallons) a day of water from desalination, which leaves a similar volume of concentrated brine. Much of the brine is pumped back out to sea, and current regulations require costly outfall systems to ensure adequate dilution of the salts to prevent damage to marine ecosystems.

A new MIT study shows that through a fairly simple process the waste material can be converted into useful chemicals — including ones that can make the desalination process itself more efficient.

The approach can be used to produce sodium hydroxide, among other products. Otherwise known as caustic soda, sodium hydroxide can be used to pretreat seawater going into the desalination plant. This changes the acidity of the water, which helps to prevent fouling of the membranes used to filter out the salty water — a major cause of interruptions and failures in typical reverse osmosis desalination plants.

Another important chemical used by desalination plants and many other industrial processes is hydrochloric acid, which can also easily be made on site from the waste brine using established chemical processing methods. The chemical can be used for cleaning parts of the desalination plant, but is also widely used in chemical production and as a source of hydrogen.

Converting the brine can thus be both economically and ecologically beneficial, especially as desalination continues to grow rapidly around the world. Environmentally safe discharge of brine is manageable with current technology, but it’s much better to recover resources from the brine and reduce the amount of brine released.

Adapted from MIT News.

Widespread PFAS Contamination Around Georgia Military Bases

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The Military Times reports widespread PFAS contamination of water in the area of Gerogia military bases as the result of years of use of firefighting foam. Nationwide, the Air Force has acknowledged contaminating drinking water in communities close to its bases in more than a dozen other states.

In Georgia, Dobbins Air Reserve Base in Cobb County, Robins Air Force Base in Houston County and Moody Air Force Base in Lowndes County used the firefighting foam in training exercises and to put out fires when planes crashed. The foam also sometimes leaked out of its storage tanks, the Journal-Constitution reported. Thousands of gallons of foam soaked into the ground or washed into creeks and wetlands, killing fish and imperiling those who use the affected waterways for fishing, swimming and boating, the newspaper reported.

The contamination, which is linked to a class of chemicals known collectively as per- and polyfluoroalkyl substances, or PFAS, was laid out in a series of site inspection reports completed by the Air Force last year.

Of particular interest in this context is the EPA’s recent decision to not establish regulatory limits on PFAS. This ruling allows the military to disclaim responsibilty for contamination of drinking water in the areas surrounding bases. In a statement, the Air Force said its response is constrained by a lack of regulation for PFAS chemicals. The two that are the focus of most testing are known as PFOS and PFOA.

“Because PFOS/PFOA are unregulated and Georgia or federal entities have not established standards for non-drinking water sources, we cannot expend government resources on those water sources,” the Air Force said.

Reference: Military Times

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Filter Arrangement Using Compact Whole House Cartridge Filters

Compact whole house filters using 4.5″x 20″ cartridges in standard “Big Blue” housings or the equivalent can be arranged to effectively support very high service flow rates with parallel installation.

 

Figure 1.

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For a single sediment filter, carbon filter, or specialty filter

Figure 2. 

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For a sediment filter followed by a carbon or specialty filter. 

Figure 3.

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For two carbon or specialty filters, each gets half the service flow.

Figure 4.

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For a single sediment filter followed by parallel carbon or specialty filters.

Figure 5.

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For a sediment filter followed by 3 carbon or media filters installed in parallel.

Figure 6.

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Bypass. Either a single filter or an entire array can be isolated with a 3-valve bypass.

Leading Water Issues, Old and New

by Emily McBroom and Gene Franks

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The statement,”my parents drank this water for 50 years, and it never hurt them” is no longer a valid excuse for consumers to not be concerned with their water quality.Greg Reyneke.

In a recent article in H2O Quality magazine, water treatment expert Greg Reyneke (see note below) commented on recent information that has surfaced about some old water treatment issues. Below are Greg’s comments, followed by some observations of our own which suggest practical approaches to dealing with the contaminants. Greg’s comments are italicized.

Arsenic

A 2010 assessment by the Environmental Integrity Project suggests that the risk of getting cancer from drinking water containing 10 ppb of arsenic is closer to 1 in 136, almost 15 times higher than current EPA assumptions (1 in 2000). Many scientists say the increased risk of cancer in humans who drink water, inhale dust, or ingest soil contaminated with high levels of inorganic arsenic puts the chemical’s danger level in the same category as that of smoking cigarettes.

 

The acceptable maximum level for arsenic in drinking water, as recommended by the EPA, is just 1/5 what it was a few years ago. Removing arsenic from a small amount of drinking water is fairly easy, while point-of-entry removal is difficult and expensive. Since arsenic is mainly an ingestion issue, we recommend removing it from drinking water and practicing common sense avoidance for other water in the home. In other words, drink water from your kitchen reverse osmosis (RO) unit, not from the bathroom sink.  The best drinking water treatment for arsenic is reverse osmosis. Undersink filters with iron oxide media are also effective.

Bacteria and Waterborne Pathogens

Bacteria exist in ALL water at some level, even safe, chlorinated city water. Some bacteria are relatively “safe,” but there are other potential problems like brain-eating amoeba that have been found in certain waters. The expense and difficulty of consistent testing often means that contamination may go undiscovered for extended periods of time.
By far the best residential treatment for bacterial contamination is ultraviolet. UV was at one time mainly used with well water, but because of growing concerns over the effectiveness of city water disinfection, and because of frequent “boil water” alerts, whole house UV units are now becoming common items in homes with municipal water. UV can also be used for point of use applications, but it costs so little extra to do the whole house, point of entry systems are most common. UV is a reliable technology that adds nothing objectionable to the treated water. It is easy and relatively inexpensive to maintain.
 

Chlorine and Chloramine

While chlorination of water is probably one of the most significant contributors to lowering the risk of waterborne illness in the USA, there are significant negative effects, such as taste and odors, corrosion, and even a correlation to the development of some cancers.
Removing chlorine or chloramine from water for the whole home or for drinking water only is best accomplished with carbon filtration. There are innumerable products to choose from, including large tank-style filters, carbon block cartridges, and even small filters built into refrigerators. Whole house filters can remove chlorine or chloramine,  but tighter drinking water filters are more effective at removing other chemical contaminants that might be present in the water. An excellent residential treatment plan is a whole house carbon filter to provide chlorine/chloramine-free water for bathing and general household purposes, and a drinking water unit, either a tight carbon block filter or reverse osmosis unit, for drinking water only. In general, chloramine is much harder to remove than chlorine. Chlormaine removal filters are larger and use better quality carbon (catalytic carbon) to do the job.
 

Hard Water Scale and Soap Interactions

While many people might consider hard water to be a simple aesthetic issue, it really is bigger than that. Hard water is a significant drain on a family’s monthly budget and has a decidedly negative impact on the planet due to increased heating and cleaning expenses, along with premature appliance failure. Consumers are clamoring for low-salt and no-salt solutions to their hard water problems that “waste” a minimum amount of water.
While there is no substitute for the conventional salt-based ion exchange water softener, salt-free alternatives, especially TAC (Template Assisted Crystallization) units, are growing in popularity fast. While TAC units don’t do some of the things softeners do, they have the advantage of requiring no salt, electricity, or connection to a drain. They don’t use water for regeneration or add salt to wastewater.

 

Lead

While Flint, Michigan, captured the imagination of the nation, lead can also be found at some level in other areas. In 2017, 779 Texas schools (about 71%) were reported to have lead in their drinking water, according to an analysis of testing data by Environment Texas Research and Policy Center. Lead is a potent neurotoxin, affecting the way children learn, grow, and behave, which can cause problems that will persist into adulthood.
Lead is a tricky issue, because lead in drinking water often comes from the pipes inside the home itself, making a “whole house” filter for lead pointless. Nevertheless, growing evidence shows that infrastructure issues, old lead city water pipes in particular, are adding lead to water coming into homes. Lead can be removed by ion exchange and by special carbon block filters with added resins, but reverse osmosis is the best treatment for drinking water. As with many contaminants, lead is mainly an ingestion issue, so having a good reverse osmosis unit in the kitchen is the most practical treatment.

Manganese

The serious health risks of consuming water containing manganese have been overlooked for far too long. Long-term consumption of even low levels are now related to complications involving alterations in neurotransmitter and enzyme levels in the brain that can cause nerve damage, brain changes, hormone alteration, and possibly even the proliferation of certain cancers.
Manganese is normally a well water issue, but we increasingly hear reports of manganese in water from central suppliers, especially small water systems. Manganese, regardless of the source, is a significant aesthetic issue, causing odors and dark stains, and it is now being regarded as a health issue as well. Whole house treatments can be complicated, but they can also be as simple as a conventional water softener or a backwashing filter. For drinking water, reverse osmosis assures manganese-free water.

 

Perfluorinated Compounds (PFC, PFOS, PFOA)

Perfluoroalkyls are not natural, and PFOA and PFOS are the two types that have typically been found in the largest amounts. These substances are unique because they repel oil, grease, and water – meaning they have been used to help produce countless convenient modern products. Exposure levels of these chemicals can already be found in the blood of most Americans. Health risks from exposure to these chemicals include hormone disruption, fertility issues, and even certain cancers.
Although treatment for perfluorinated compounds in municipal systems can be complex, carbon filtration for whole house and reverse osmosis for drinking water have been found to provide significant reduction for homes.

Nitrates

One other issue we would like to add to the list of regulated contaminants that should be taken more seriously is nitrates.  There is growing evidence that nitrate contamination is becoming much more common, not only in well water but also in city water supplies. The long-standing EPA allowable amount of 10 parts per million may be way too lenient. Although nitrates can be removed with ion exchange, the best and easiest way to provide nitrate-free drinking water is with an undersink RO unit in the home.

Conclusion

 

Of the issues discussed, whole house treatments are practical for bacteria and hardness. For city water with chlorine, chloramine, and general chemical issues, including PFOS, an appropriately designed and sized whole house carbon filter is recommended. For drinking water issues like lead, nitrates, and arsenic, an undersink reverse osmosis unit is the treatment of choice. A good undersink RO unit covers virtually all drinking water issues. It includes tight carbon block filters for chemical reduction and a very tight membrane that strains out lead, arsenic, fluoride, nitrates, sodium, and other undesirables.

Reference: Greg, Reyneke, “It’s Up to You,” H2O Quality (a publication of the Texas Water Quality Association), Winter, 2019.  pp. 10-12.  See also www.gregknowswater.com .

Bacteria vs Fatberg


Posted February 3rd, 2019

Fatbergs and Bacteria

 

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In September 2017, sewer workers in London discovered a “fatberg” made of oil and grease poured down London drains mixed with flushed wet wipes, diapers, and condoms that failed to disintegrate. This fatberg weighed in at 130 tons, the weight of about 19 African elephants, and stretched 820 feet, almost the total length of the London Bridge. Though it was cleaned out by the heroic efforts of sewer workers, a bit of the monster fatberg remains and can be seen at the Museum of London.

Fatbergs,  at the same time disgusting and somewhat comical,  give us an insight into the alien world of the sewer networks that keep towns and cities running smoothly. Fatbergs are pretty spectacular. They can shut down an entire municipal drainage system and they can cost millions of dollars to clear.

The famous fatberg pictured above is from London, but fatbergs exist everywhere, and not just in big cities.  The English seaside town of Sidmouth recently discovered a fatberg of gigantic proportions.

Fatburgs come at a big cost. Every year the UK spends an estimated £100,000,000 clearing away some 300,000 fatbergs created by congealed fats and waste that people pour down the sink and flush down the toilet. In addition to fats, diapers, so-called “disposable” wipes, and condoms are big contributors to fatberg formation.

Historically, water companies have resorted to the hard task of physical removal to keep drains clean. Cleaning away a fatberg often requires truly heroic efforts on the part of water treatment workers,

Bacteria to the rescue

A German company, however, has taken a new approach to the removal and prevention of fatbergs. A product called Lipasan, made in south-west Germany, treats fatbergs with a micro-organism solution made with bacteria grown specifically to eat fat.  Lipasan digests fat, grease, and oil.

Lipasan is being used with great success in the German city of Ramstein which has a particular problem with fatberg formation, because, according to a company spokesperson, “the city has a US Military base, which has brought with it a cuisine that is traditionally higher in fat.” Military bases are infamous in the US for contaminating their surrounding areas with water polluting chemicals. Currently PFAS has drawn most attention for military water pollution, but everything from trichloroethylene to benzene to mercury have been found in abundance in waters in the neighborhoods of military bases such as Camp Lejeune, NC. Perhaps fatbergs can be added to the list of the side effects of the military.

According to Dr. Andrea Junker-Buchheit, a lead scientist in the creation of Lipasan, “We treat fatbergs with a special micro-organism solution. We grow bacteria which have been developed specifically to eat fat. They digest all the fat, all the grease, all the oil.” The bacteria eats fat, and needs more and more of it to survive and grow.

The application of Lipasan consists of the use of dosing pumps to inject specific amounts of the bacterial solution into the pipes of the water treatment plant. The injected bacteria keep the pipes clean and fatbergs under control. Although preventive treatment with fat-gobbling bacteria is not cheap,  the cost is only a fraction of that of clearing fatbergs from pipes using conventional means.

Reference: BBC.

More about fatbergs from the Pure Water Gazette.

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Research casts doubt on EPA drinking water standard

by Justine Calma

More than 5 million Americans get their drinking water from public water systems that could contain hazardous levels of a chemical called nitrate, which is linked to public health risks — including cancer and birth defects. And the concentrations found in the vast majority of that drinking water would be deemed safe by the Environmental Protection Agency, according to a study published this month in the journal Environmental Health.

Nitrate occurs naturally in soil, water, and food. But when it is ingested, it can react with organic compounds in the body to form carcinogens.

A team of researchers at environmental health advocacy groups looked into nearly 40,000 public water systems that between 2010 and 2014 served 70 percent of Americans. They found that more than 1,600 of the systems they reviewed had average nitrate concentrations of at least 5 parts per million.

While that amount is just one-half of the level that the Environmental Protection Agency deems safe to drink, the lead study author told Grist that there is evidence that the federal standards may be outdated.

“The EPA is very slow in updating drinking water standards,” said lead author Laurel Schaider, a research scientist at the Silent Spring Institute, a non-profit research group in Massachusetts that studies the effects of chemicals on women’s health. In fact, just this week, Politico reported that the EPA won’t place federal limits on two chemicals associated with cancer and other health issues in drinking water — despite lawmakers on both sides of the aisle pressuring Andrew Wheeler, the agency’s acting administrator, to take action.

The EPA established 10 parts per million as its regulatory standard for nitrate in 1991 primarily to protect infants from “blue baby syndrome.” The syndrome, which can impact infants who are fed formula mixed with nitrate-contaminated water, causes a drop in in the amount of hemoglobin in the blood, which cuts the babies’ oxygen intake.

It’s unclear whether the EPA is considering revising its safety standard. In a December 2016 review of drinking water standards, it designated nitrate as “not appropriate for review at this time.” But in September 2017, the agency released a draft plan to reassess the health effects of nitrate, noting that health studies published since 1991 had called into question whether the EPA’s current maximum nitrate contaminant levels “provide adequate health protection for the general population.” The EPA declined to provide a comment to Grist.

Several studies have documented increased health risks — ranging from colorectal cancer, thyroid disease, and birth defects affecting the brain, spine, or spinal cord — stemming from elevated nitrate levels, even at concentrations below current federal regulatory limits. For example, a 2013 study of more than 4,000 mothers found that women who consumed water with levels well below the EPA limit were roughly twice as likely to deliver babies with birth defects. And a 2010 study of more than 21,000 women in Iowa documented an increased risk of thyroid cancer for people exposed to nitrate levels in public water supplies that were greater than 5 ppm for five or more years.

Although 99 percent of water systems surveyed in the Silent Spring Institute’s analysis showed nitrate levels below the EPA’s 10-ppm standard, 129 community water systems serving 144,000 Americans had an average nitrate concentration surpassing that upper limit. Private drinking wells weren’t included in this study, but are often located in rural and agricultural areas, where that study shows there tends to be more nitrates that can seep into the groundwater.

The biggest culprit for nitrate contamination is runoff from fertilizers or manure. That could point to why states in the West and Midwest, home to eight of the top 10 agriculture-producing states, had higher levels. The increased use of fertilizers, more prominent fossil-fuel combustion, and the growing popularity of nitrogen-fixing crops like soybeans have led to a doubling of the natural rate at which nitrogen is deposited into land since the 1920s.

Schaider’s team also found that water systems that served populations with a larger proportion of Hispanic people tended to have higher levels of nitrates. The researchers hypothesized that the correlation was due to the group’s association with agricultural work. But Hispanic residents didn’t appear to have high exposure to nitrates in the Midwest, suggesting a different explanation for the community’s outsized link to nitrates in their water.

Mary Ward, a senior investigator at the Occupational and Environmental Epidemiology Branch at the National Cancer Institute and a leading expert on nitrates, lauded the new research, which relied on publicly available data collected by EPA under the Safe Drinking Water Act, as the first assessment of the U.S. population’s potential exposure to nitrates through their public tap water.

Since most health studies on nitrate to date have focused on populations using public water supplies, a majority of the findings are for exposures below the EPA’s maximum contaminant level, said Ward. After all, public water utilities are mandated to provide drinking water that meets EPA safe-drinking standards.

Ward adds a note of caution when it comes to raising the alarm on nitrate levels below that current standard: “We need additional studies,” she wrote to Grist in an email. “The number of well-designed studies of these health outcomes are still too few to draw firm conclusions about risk.”

The study authors write that the issue merits further study, since nitrate has also been found to occur alongside other pollutants present in drinking water, including arsenic, pesticides, and other chemicals used to filter water. Robust monitoring of nitrate, the say, could be one way to improve water quality overall.

Article Source: Grist.

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