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Coronavirus And The Water Cycle — Here Is What Treatment Professionals Need To Know
As the global health community tracks the spread of this virus, it’s important for water and wastewater professionals to keep updated on potential impacts
Guest Column | March 5, 2020
By Nicole McLellan, David Pernitsky, and Arthur Umble
As the global health community tracks the spread of this virus, it’s important for water and wastewater professionals to keep updated on potential impacts.
It's hard to miss the headlines. The recent outbreak of novel coronavirus (2019-nCoV or COVID-19) has dominated news cycles in recent weeks. The World Health Organization (WHO) is calling it “public enemy number one.” But what information do we have that is related to coronaviruses in water and wastewater systems? And what can water- and wastewater-system operators do to protect public health?
Modern water and wastewater treatment systems play an important role in public health protection. With the potential for environmental transmission, water and wastewater operators need to know the potential for survival of this type of virus in water and wastewater treatment systems.
Coronaviruses, named for the crown-like spikes on their surface, were first identified in the mid-1960s. Currently, seven coronaviruses are known to infect people and make them ill. Three of these — MERS-CoV, SARS-CoV, and COVID-19 — emerged in the last 20 years and are examples of how some coronaviruses that infect animals can evolve to infect humans. COVID-19 is a new variety of coronavirus and is an enveloped, single-stranded (positive-sense) RNA virus.
So, what is the fate of coronavirus in sewage and wastewater treatment plants? Or in the aquatic environment? And should we be worried about the efficacy of water treatment filtration and disinfection processes for coronavirus removal and inactivation?
The short answer: No — if we take proper precautions and risk considerations.
The long answer: This is a new virus without an extensive body of literature on the effectiveness of water and wastewater treatment processes. And real-life experiences will vary due to water quality and treatment plant details.
According to a 2008 University of Arizona study, coronaviruses have not been found to be more resistant to water treatment than other microorganisms such as E. coli, phage, or poliovirus — which are commonly used as surrogates for treatment performance evaluations. Results from bench-scale studies suggest that the survival of coronaviruses is temperature-dependent, with greater survival at lower temperatures. Therefore, coronavirus is expected to be reduced in raw wastewater and surface waters in warmer seasons.
How is it transmitted?
Human viruses do not replicate in the environment. For a coronavirus to be transferred via the water cycle, it must have the ability to survive in human waste, retain its infectivity, and come in contact with another person — most likely via aerosols. Findings suggest that COVID-19 can be transmitted through human waste.
Should a major virus pandemic occur, wastewater and drinking water treatment industries would face increased scrutiny. Utilities would need to respond rapidly to minimize occupational and public health risks based on the available evidence. Wastewater effluents would possibly impact recreation, irrigation, and drinking waters. While wastewater treatment does reduce virus levels, infective human viruses are often detected in wastewater treatment plant effluent.
Information for wastewater treatment plant operators
Typically, human waste entering a sewage system is carried through an underground pipe system to a municipal treatment plant. Wastewater treatment plants receiving sewage from hospitals and isolation centers treating coronavirus patients — and domestic sewage from areas of known large contamination — may have elevated concentrations of viruses. Wastewater is treated by a variety of processes to reduce the pollution impacts on nearby receiving waters (lakes, rivers) and disinfected.
Currently, major data gaps exist on the potential role of the water cycle in the spread of enveloped viruses. The lack of detection methods for these strains of viruses is a main reason this type of information is still relatively unknown. Most detection methods are designed and optimized for non-enveloped enteric viruses, and there just isn’t enough information available.
In general, secondary wastewater treatment is credited with removing 1-log (90 percent) of viruses, though broad studies suggest the level of virus removal is highly variable, ranging from insignificant to greater than 2-log removal (99 percent). Because of this variability, the primary process for the inactivation of viruses in wastewater treatment is chemical disinfection (e.g., chlorination) and/or by ultraviolet light.
Drinking water treatment is an effective barrier
Surface-water treatment plants with upstream wastewater impacts are the most susceptible to having coronavirus contamination in the raw water supply during, and after, an outbreak. Viruses are exposed to several potentially inactivating stresses in surface waters, including sunlight, oxidative chemicals, and predation by microorganisms. Generally, enveloped viruses are more susceptible to common drinking water disinfectants than non-enveloped viruses.
Based on published research, water treatment processes that meet virus removal/inactivation regulations are effective for coronavirus control.
For example, drinking water quality guidelines from Health Canada note conventional treatment with free available chlorine can achieve at least 8-log inactivation of viruses in general. Of course, disinfection performance must be continuously monitored (e.g., turbidity, disinfectant dose, residual, pH, temperature, and flow). Optimized conventional filtration can achieve 2-log (99 percent) virus removal and is just one of many processes water treatment facilities incorporate to make our water safe to drink.
Modern drinking water treatment plants are well equipped to remove and disinfect viruses through filtration and disinfection processes.
So now what?
By and large, these viruses are not considered a major threat to the wastewater and water industries due to their low concentrations in municipal wastewater and high susceptibilities to degradation in aqueous environments. According to new OHSA guidance, there is no evidence to suggest that additional, COVID-19-specific protections are needed for employees involved in wastewater treatment operations.
The WHO found that risk communication and community engagement (RCCE) has been integral to the success of response to health emergencies. Action items related to coronavirus include communicating about preparedness measures and establishing a system for listening to public perceptions to prevent misinformation.
Basic recommendations for treatment-plant operators when dealing with a potential virus outbreak
So far, this virus does not appear to survive well in the environment and can be eliminated effectively by water treatment, especially chlorination, and would pose a minimal risk through drinking water. As the outbreak continues, more water-quality experiments are needed before major conclusions can be drawn on their fate within treatment processes. While this will be tricky, especially as viruses continue to replicate and evolve, quantitative risk assessments should be a top priority for enveloped viruses in wastewater, recreational waters, and drinking water.
Treatment-plant operators can download this white paper for more details on the current state of knowledge on coronaviruses as it relates to our practice. For additional reputable and reliable sources of information that are updated frequently with technical guidance, public health information, and the latest research visit the Water Environment Federation’s coronavirus site.
Lead Photo: The spikes on the surface of coronaviruses give this virus family its name — corona, which is Latin for “crown.”
About the authors
Nicole McLellan is an environmental scientist. She has an academic background in environmental microbiology and civil engineering for drinking water treatment performance evaluations.
David Pernitsky is the global practice leader for water treatment. He has more than 25 years of environmental engineering experience, managing many challenging studies.
Arthur Umble is Stantec’s global lead for wastewater practice. He develops strategies and provides solutions for complex wastewater treatment challenges.
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Comments (9)
We must thank the authors for this sensible evaluation of the public health risks from Coronovirus Corvid 19. It would appear they are indicating that there are potential risks from Coronovirus in wastewater for example aerosols from uncovered activated sludge aeration tanks and in discharging untreated sewage into cold (bathing) water through Combined Sewer storm Overflows of which there are 31,000 in the UK alone.
Matthew· 2 weeks ago
Hmm, I have one of these uncovered sludge aeration tanks on the other side of my fence downwind of my garden and house. Seems I'm right to be concerned?
Ben Tangena· 3 weeks ago
Of course, chlorination, UV or Reverse Osmosis in drinking water treatment are effective barriers against all viruses, also coronavirus. But what will happen if such a barrier fails? Then the coronavirus can spread through the distribution system. What is the risk if you drink such contaminated water? In other words: Is the oral intake of coronavirus a significant route for infection?
1 reply · active 3 weeks ago
Vadim Malkov· 3 weeks ago
This is why we need to stick to WQ monitoring - you cannot control what you do not measure!
kondala rao g· 3 weeks ago
Very informative article and quite useful in understanding the impact of controlling corona viruses in water and wastewaters.
Very good article, very focused, especially in this time of exaggeration and disinformation. Based on what the author has stated, I would like to highly recommend the reliable and sustainable online disinfection system (directly on the water stream): BlueSense OXAQUA manufactured in the Netherlands, is a natural generator of Electrochemically Activated Water (ECA Water). This system produces hypochlorous acid (HOCI) naturally in drinking water to disinfect flows of up to 10 m3 / hour, without adding chemicals or precursors such as sodium chloride (the concentration must be greater than 20 ppm of chlorides). OXAQUA also creates a residual oxidant up to the point of use by the end-user. OXAQUA uses chlorides naturally present in water to generate up to 2 ppm of free chlorine in the form of hypochlorous acid. This strong oxidant is known to prevent the spread of bacteria, viruses, algae, and molds in drinking water and hot water systems.
Ray Walton· 2 weeks ago
This info seems to be deliberately 'suppressed' here in the UK.
Is CORONAVIRUS - COVID-19 present in Raw Sewage? …
YES…AND STILL, THE RAW SEWAGE IS BEING DISCHARGED INTO UK RIVERS, STREAMS, CANALS, SEA, ETC. BY UK PRIVATISED WATER AND SEWAGE COMPANIES NATIONWIDE AND AUTHORISED BY GOVT AND THE ENVIRONMENT AGENCY… TO PROFITEER AND SAVE MONEY ON PROPER SEWAGE TREATMENT THAT WOULD SOMEWHAT LESSEN THE RISK OF SPREADING THE CONTAMINATION... THE PUBLIC PAY FOR RAW SEWAGE TREATMENT IN THEIR WATER AND SEWAGE BILLS.
Chris· 1 week ago
This comment is disturbing knowing I work with alot of people who work in the sewer still everyday even today.... I am self isolating after coming home out of country
Philip Monro· 3 days ago
Am I over concerned regarding the amount/concentration of "human sewage" if there are conference halls being filled with 2000 beds where the plumbing for that conference hall was never designed for the safe disposal/disinfection of "human sewage". Am I also being alarmist as to the low probability of the conference center's "wastewater supply AND THE MAIN DRAINS THEY ARE CONNECTED TO to being "with minimum / fast/temporary wastewater plumbing coping? FINALLY, if this error leads to massive, wider contamination (or even rupture of the system) just how will this significantly larger network of pipe-work be safely disinfected at ACCEPTABLE intervals and with potential repairs if ruptured? Dr. Philip Monro PhD
US: Wisconsin - UW Researchers Find Microplastics In BWCAW
We’ve already known that microplastics are floating throughout Lake Superior, that they are in our drinking water, that they are in fish we catch and that they are even in our beer
Tiny Bits of Plastic Have Turned Up In Worms,
Soil, And Water In The Supposedly Pristine Wilderness.
Written By: John Myers | October 25, 2019
UW-Eau Claire students Reed Kostelny (left) and Thomas Adams are part of a research team that found microplastics in earthworms, water and soil in the BWCAW. (Photo courtesy UW-Eau Claire)
We’ve already known that microplastics are floating throughout Lake Superior, that they are in our drinking water, that they are in fish we catch and that they are even in our beer.
So maybe we shouldn’t be surprised that researchers from the University of Wisconsin-Eau Claire have found tiny pieces of plastic in the Boundary Waters Canoe Area Wilderness, the most pristine area of the Northland.
Researchers found microplastics in earthworms, in the water and in the soil that they collected this summer from sites within the BWCAW, said Todd Wellnitz, professor of biology and the faculty leader on the research project.
“We found 80 pieces of microplastics in one earthworm that we examined,” Wellnitz said in a statement. “That blew me away.”
Plastics that are less than five millimeters in length, about the size of a sesame seed, are known as microplastics. They can come from a variety of sources, including synthetic clothing, soaps, toothpaste, plastic packaging and containers such as water bottles.
While microplastic beads have been banned from many consumer products, hundreds, even thousands, of plastic fibers can be shed from one fleece garment every time it’s washed. And larger pieces of plastic — including water bottles, plastic bags and packaging of all sorts — eventually break down into microplastics when left out in the environment. Once they reach the micro size, they seem to persist indefinitely.
While significant research has been done on the presence of microplastics in oceans, rivers and the Great Lakes, less has been done on plastics in smaller, freshwater lakes.
"We're finding microplastics in the Boundary Waters, and that’s a big deal,” Wellnitz said. “No place is pristine now; microplastics are everywhere. It’s all over the planet, and we’re just realizing it.”
The UW-Eau Claire research team, including, from left, Megan Vaillancourt, Todd Wellnitz and Monica Dickson, is continuing to study samples of soil and water taken from the BWCAW during two trips there this summer. Photo courtesy UW - Eau Claire.
After finding microplastics in the earthworms on a June excursion, the researchers returned to the BWCAW in August, this time collecting soil, water, earthworms and crayfish samples.
The samples were collected from areas primarily near campsites, said Reed Kostelny, a junior environmental biology major from Appleton, Wis. They found the most microplastics in samples taken from the lake closest to the Boundary Waters entry site.
“We know that earthworms do consume microplastics,” Kostelny said of their findings. “Now that we have our early data, we want to know more about the worms and how the microplastics could move up the food chain.”
Since birds, fish, and other wildlife consume earthworms, microplastics have likely already entered the food chain in the Minnesota wilderness area, Wellnitz said.
Earthworms are not native to the Boundary Waters area but are brought in by visitors who come to fish the many freshwater lakes found within the area, said Megan Vaillancourt, a senior microbiology major from Stillwater, Minn.
“Fishermen bring the worms in, and the worms are ingesting the plastics we bring in with us,” Vaillancourt said. “That’s a double negative for the area.”
Most visitors do embrace the “leave no trace” mantra in the BWCAW. But microplastics shed easily, so they may be coming from clothing, blankets, tarps and other supplies that visitors routinely bring into the Boundary Waters, Vaillancourt said. Since microplastics are so small that they can’t easily be seen, people have no idea they are leaving them behind.
Microplastics also can move from place to place via rain or wind, so they likely are entering the Boundary Waters in multiple ways, the researchers said.
Microplastics first made News Tribune headlines in 2013 after scientists, including Lorena Rios-Mendoza, assistant professor of chemistry at the University of Wisconsin-Superior's Lake Superior Research Institute, dragged super-fine mesh across the Great Lakes and caught millions of plastic pieces.
In a study published in 2018 in the journal Plos One, Mary Kosuth, a master's graduate of the University of Minnesota School of Public Health, found that eight of nine tap water samples taken from all five Great Lakes had plastics in them. And Kosuth, a Duluth native, found that all 12 brands of beers she tested brewed with Great Lakes water had plastics inside. It's a global phenomenon, she noted, with a 2014 study reporting plastic found in 24 brands of German beer.
Kosuth also looked beyond the Great Lakes and looked at tap water from 159 municipal sources from 14 countries, with 81% carrying plastic particles.
Kosuth noted that global plastic production has skyrocketed from 30 million tons in 1970 to 322 million tons in 2015, and each year more of that stuff ends up in the environment. She echoed what Northland researchers and conservation activists have said for years: If you want to get plastic out of the lakes and oceans, you need to get it out of your hands and your home.
The News Tribune in 2016 reported a study by Rochester Institute of Technology researchers that estimated nearly 22 million pounds of plastics enter the Great Lakes every year.
Those products get blown (or thrown) into the lakes and eventually disintegrate into plastic bits, some of them smaller than grains of sand. But the plastic bits never go away, and they have spread across the Great Lakes ecosystem.
Scientists say the human health ramifications of ingesting plastic in the water, beer, fish and other items remain unknown. Not only may the plastic itself be bad but the bits can also carry other contaminants.
The EPA's Rollback of the Clean Water Act Could Impact Drinking Water For Millions of Americans
"They're effectively sending us back 30 years in our protections of U.S. waters," says Peter Gleick, co-founder of the Pacific Institute and a MacArthur "genius" Fellowship winner for his work as a climate and water scientist
It exposes small streams and wetlands nationwide to pollution
By Ula Chrobak
September 13, 2019
The Trump Administration just announced yet another blow to the country's environmental protections. On Thursday, officials from the EPA and the U.S. Army Corps of Engineers repealed an Obama administration update to the 1972 Clean Water Act, which had expanded protection to wetlands and streams that are disconnected from navigable rivers. "They're effectively sending us back 30 years in our protections of U.S. waters," says Peter Gleick, co-founder of the Pacific Institute and a MacArthur "genius" Fellowship winner for his work as a climate and water scientist.
The 2015 rule has broadened the definition of "waters of the United States," which allowed the EPA to regulate pollutants in a much greater proportion of waterways than before. Dry washes and streams may only flow intermittently, but according to an EPA report, they make up about 59 percent of streams in the U.S. and 81 percent of those in the Southwest. Another EPA report, which supported the 2015 rule, reviewed more than 1,200 studies on small streams and wetlands and found that they're critical to the health of downstream rivers: "There is ample evidence that many wetlands and open waters located outside of riparian areas and floodplains, even when lacking surface water connections, provide physical, chemical, and biological functions that could affect the integrity of downstream waters." And yet, many of these waters now have no protection under federal law.
The original definition of "waters of the United States" mainly covered large rivers, their tributaries, and adjacent wetlands. The Clean Water Act requires industrial and municipal polluters discharging to these rivers to obtain permits from the EPA and the 2015 update expanded those regulations to include smaller streams and wetlands. Thursday's repeal will soon be followed by a rule change, and the replacement text would basically revert to the '70s-level protections. Officials have stated that the change would remove a current "regulatory patchwork"—the 2015 update only applies to 22 states, Washington D.C. and U.S. territories because other states have challenged the rule in court. In a press release, EPA Administrator Andrew Wheeler said redefining "water of the United States" would "provide greater regulatory certainty for farmers, landowners, home builders, and developers nationwide."
But despite whatever uncertainty there may have been, the 2015 update was enacted for a reason: the streams and wetlands that aren't flowing into or right next to major rivers are still crucial for wildlife and humans. Drinking water for one in three people in the lower 48 comes from same waters that just lost their federal protections in the repeal, as PopSci has reported previously. "The weakening that we're seeing today is really serious—It's really cutting protection for drinking water for a lot of Americans," says Gleick. "A lot of our groundwater resources and a lot of our surface water resources are now going to be vulnerable to far more pollution."
The 2015 rule also regulated pesticides and nutrients leaching from many farmers’ fields—a diffuse but cumulatively significant source of pollution. In the Mississippi basin, for example, the pollutants from numerous farms that trickle into small streams and wetlands eventually flow into the river and then into the Gulf of Mexico says, Gleick. This impacts water quality and leads to the growth of massive algal blooms and fish die-offs. “Some farmers would have had to get permits to discharge pollutants into the streams and wetlands,” says Gleick. But now that requirement has been lifted, and our waters will suffer for it.
Lead Photo: Small streams could be in danger / Joao Branco/Unsplash
Massive Waves of Toxic Seaweed Inundate Yucatan Shorelines
It is the biggest algae bloom in the world: Massive waves of seaweed called sargassum washing up on shore day after day
CBS NEWS July 27, 2019, 9:24 AM
It is the biggest algae bloom in the world: Massive waves of seaweed called sargassum washing up on shore day after day.
Jose Escalante, who has owned a small hotel in Tulum, Mexico, for eight years, said seaweed, which had been cleaned from the beach that day, will again cover the shoreline in a couple of hours.
Every day workers here in Tulum, and up and down the Yucatan Peninsula, remove tons and tons of decomposing sargassum from beaches. And every night it comes back.
The Caribbean's pristine beaches and crystal-clear waters are under threat from the newest manifestation of a changing planet: Waves of toxic seaweed, sargassum, which are washing ashore on the Yucatan Peninsula. CBS NEWS
Rosa Rodríguez-Martínez, from Mexico's National University, is trying to figure out why. She said sargassum used to wash ashore for two or three weeks during the summer. Now? "We are getting sargassum almost from March to October," she told "CBS This Morning" co-host Jeff Glor. "So basically, more than half of the year we are receiving massive amounts."
"That's a huge difference," said Glor.
"It's impressive," she said. "It's a problem. Economical problem, ecological, and probably a human health problem also."
Since 2011 the amount of sargassum in the Atlantic has increased dramatically. It currently forms a 5,000-mile mass from Africa to the Caribbean. It is estimated to weigh 22 million tons.
Why is it so bad right now? "I think it's because we have polluted the sea too much," said Rodríguez-Martínez. "So, now we have a lot of nutrients [in the ocean], and the algae are taking advantage of it."
Fertilizer run-off from Brazil, increased by deforestation, is believed to be the largest fuel source for the sargassum. That, combined with warming ocean water and changing ocean currents, has put the Yucatan squarely in the crosshairs.
It has gotten so bad the Mexican navy has just been put in charge of dealing with it.
They took Glor up in a reconnaissance mission to locate the largest sargassum waves.
An aerial view of the masses of sargassum inundating Mexico's shorelines. CBS NEWS
"We are fully aware that we are only addressing the effects of sargassum," said Rear Admiral Enrique Flores Morado, who said the navy will build new sargassum-busting ships to reel in as much as they can. "But that does not solve any problem. In reality the causes have to be addressed. But given the lack of research, we are now implementing immediate actions."
Right now, many towns, and resort owners, are using floating barriers to corral and collect sargassum, including in Puerto Morelos, half an hour south of Cancun.
Corralling the algae bloom. CBS NEWS
"We can say for sure that we are the first destination in the whole Mexican Caribbean with already a control about the sargassum," said Héctor Tamayo, director of tourism for Puerto Morelos.
"There's a lot of it, though. It doesn't look controlled," said Glor.
Tamayo said there are more than 50 trucks every day carting out sargassum.
And some are developing novel ways to use sargassum, including Omar Vasquez, who is building homes with it. Vasquez mixes with sargassum with clay and compost, which is then compressed into bricks.
"They're better than the other bricks," he said. "It does not have even a gram of cement. Everything is organic.
"I mean, it's ironic because I grew up without a house, without a home. We crossed the border to the States when I was eight years old. I came back to live my Mexican dream!"
Omar Vasquez shows Jeff Glor the bricks he makes by mixing sargassum with clay and compost. CBS NEWS
Even though Vasquez says his homes are 100-percent organic, there may be an issue with what accumulates in the sargassum at sea.
Rosa Rodríguez-Martínez's latest research shows sargassum is high in heavy metals, like lead and arsenic. And disposal is a major issue.
Sargassum is either being dumped inland, or buried under the beach, which is illegal.
One dump site where the sargassum is taken is in the jungle, miles away from the ocean. It's unclear if the sargassum left there seeps into the ground, goes up into the air, or will just sit there forever.
It is a crisis stretching across the Caribbean, with no end in sight.
Glor asked Escalante, "For folks watching this who may not be familiar with this problem or what's happening here, what do you say?"
"It's something that is happening to the world, not just to the region," he replied. "This is just a consequence of the entire planet being in trouble."
See also:
Massive Algae Blooms Choking Waterways, Synthetic Fertilizers in Chemical-Intensive Land Management a Major Cause
In the food chain, as in all systems, balance is key; but in Florida, erupting algal blooms are evidence of a system wildly out of balance.
(Beyond Pesticides, July 20, 2018) Algae are elemental to life on Earth as generators of most of the planet’s oxygen and as food for myriad organisms. In the food chain, as in all systems, balance is key; but in Florida, erupting algal blooms are evidence of a system wildly out of balance. Blue-green algae species are coating the surfaces of many of the state’s lakes. In the past month, algae on the state’s most-well-known water body — Lake Okeechobee — grew from a crescent in one corner of the lake to 90% coverage of its 370 square miles. Algae have grown out of control in part because of nitrogen and phosphorus pollution, which arises from runoff from conventionally managed lands and from leaky septic systems. Beyond coating the lake surface, the slimy stuff is now found not only in the Caloosahatchee River, but also, along its entire canal system from Lake Okeechobee into downtown Fort Myers, and moving toward the river’s mouth on the southwest coast. Indeed, in early July, after touring the Caloosahatchee River estuary, Florida’s governor issued an emergency order to help state agencies in multiple counties better manage these harmful algal blooms in lakes, rivers, and coastal estuaries.
Such algae overgrowth arises from a concurrence of basic ingredients: ample warm water (think summer), sunlight, and pollution. Given that it is nigh impossible to control sunlight or water temperature — and water temperatures and extreme spring and summer rain events will likely worsen, given climate disruption — humans can have the greatest impact via their own contributing activities. The U.S. Environmental Protection Agency (EPA) indicates that, “The most effective preventative measures are those that seek to control anthropogenic influences that promote blooms such as the leaching and runoff of excess nutrients. Management practices for nutrients, specifically nitrogen and phosphorus, should have the goal of reducing loadings from both point and nonpoint sources, including water treatment discharges, agricultural runoff, and stormwater runoff.”
Put simply: nitrogen and phosphorous, characteristic of agricultural runoff from the use of synthetic fertilizers, boost algal growth. The extremely common use of such fertilizers in chemical-intensive (conventional) agriculture and turf care is a huge contributor to the problem.
A primary fix for the epidemic of algal blooms is curbing nutrient pollution by avoiding use of synthetic fertilizers in agriculture, and in turf and landscape management (of golf courses, sports fields, lawns and gardens, etc.). The optimal way to do that is to adopt organic agricultural and land management practices. A Beyond Pesticides Pesticides and You journal article from 2014 notes, “Organic standards stipulate that soil fertility and crop nutrients can be managed through tillage and other cultivation practices, such as crop rotation [and use of compost as fertilizer], which preserve and maintain the fertility of the soil so that synthetic inputs become unnecessary. Organic, therefore, eliminates the need and use of synthetic nitrogen- and phosphorus-based fertilizers, thereby significantly reducing the threats that nitrogen and phosphorus runoff have on aquatic ecosystems and the prevalence of algal blooms and eutrophication [overgrowth of plant life and death of animal life from subsequent lack of oxygen].”
Synthetic fertilizers contain water-soluble nutrients, some of which are not absorbed by plants, but settle in the soil and then migrate toward groundwater and ultimately, water bodies. Organic agricultural and turf management practices, such as the use of compost to boost soil fertility — rather than dumping synthetic fertilizers into the soil — are effective solutions to the problem.
Organic methods feed the soil, rather than feeding plants directly. Organic fertility and soil amendments (such as compost) are not water soluble; they feed the microorganisms in the soil and the breakdown products of that process release nutrients that then feed plants. This slower process does not result in the runoff associated with water-soluble synthetic materials. The 1990 Organic Foods Production Act established regulations that permit only those soil inputs that do not adversely affect the “biological and chemical interactions in the agroecosystem, including the physiological effects of the substance on soil organisms.” Synthetic fertilizers are prohibited in certified organic systems. As Beyond Pesticides noted in the Fall 2017 issue of Pesticides and You, “While chemical-intensive land management relies on synthetic fertilizers that are soluble chemicals taken up by the plant and prone to run-off into waterways, organic systems rely on feeding the soil microbes, which in turn produce solubilized nutrients that are absorbed by the plant.”
Researchers on the issue of algal blooms and “dead zones” in Lake Erie (and other Great Lakes) were able to pinpoint the two major factors that explain their observation of marked increases in dissolved reactive phosphorus, which is nearly 100% bioavailable to algae. Those factors, they concluded, were “a combination of agricultural practices that have been put in place since the late 1980s and into the 2000s, combined with increased storms, particularly higher intensity spring rain events [attributable to climate change].” The agricultural practices the researchers' reference include a shift toward more fall fertilizer applications instead of spring applications, the use of broadcast fertilizer that does not integrate into the soil, and an increase in no-till field management that leads to a build-up of phosphorus in the top layers of soil. No-till methods concentrate fertilizers near the soil surface where they are more likely to wash away during strong storms.
People, of course, don’t like to see their favorite lakes or rivers covered in green slime. But the problems with algae overgrowth are not only aesthetic: the blooms choke off sunlight to underwater organisms that require it for photosynthesis, deplete oxygen in the water and deprive other organisms of it, and can spread to ancillary water bodies. These conditions can cause the above-mentioned “dead zones” — hypoxic (low-oxygen) areas in large water bodies that cannot support most marine life in lower-level water. Sometimes, toxic subspecies of algae appear and present health risks (including liver and brain diseases).
In addition, the fertilizers that spur this growth can contaminate groundwater, including those aquifers used as sources of drinking water. A 2013 study found that synthetic nitrogen from fertilizers (as nitrates) leaches from soil toward groundwater over the course of decades, meaning that the agricultural and land management activities of as long as 50 years ago may still be affecting water bodies. Nitrate is a common contaminant of drinking water in agricultural areas where nitrogen fertilizers are used. Another “bonus” is that intensive use of synthetic fertilizers may increase the nitrate levels found in certain vegetables, such as lettuce and root crops. Research has indicated that long-term dietary exposure to nitrates may increase risk of thyroid disease (because nitrate competes with the uptake of iodide by the thyroid gland, potentially affecting thyroid function).
To combat algal blooms and their harmful impacts, Beyond Pesticides recommends advocating for organic agriculture, purchasing organics to leverage demand in the marketplace (and thus, protect human and environmental health), and encouraging organic land management at the local level (city, town, and/or county). For assistance with such advocacy in your community, contact Beyond Pesticides at info@beyondpesticides.org or 1.202.543.5450.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: https://www.miamiherald.com/news/local/environment/article214620390.html