Aging Septic Systems are Contaminating Water in Florida with Nitrogen and Pathogens: A Shallow Water Table and Porous Soil Allow it to Spread

      The type of septic system installed, how deep, and sometimes how large the leach field is, depends on the characteristics of the soil. Septic leach fields are installed as shallow as possible to take advantage of higher oxygen levels in the soil nearer the surface so that the aerobic bacteria can thrive to break down the organic matter in the effluent coming from the septic tank. They are also installed shallow to stay above the water table. Other types of systems do not utilize a leach field, but some type of chamber filled with mulch or sand where the water is treated. In Florida, the soil is generally quite porous, and the water table is high. This complicates septic system optimization and can lead to failed and dysfunctional systems where the effluent is not being adequately treated.

     Florida’s problem is mainly aging septic systems that are no longer functioning adequately. According to environmental scientist Iuliia Istratiy, reporting for the Sun Sentinel:

“Florida has more than 2 million septic systems, one of the highest numbers in the country. Many of them were installed decades ago, long before today’s environmental standards and rapid population growth. While septic systems are often seen as a private household issue, taken together, they have become a major public and environmental concern."

     These systems were generally not designed to remove nitrogen, and with the porosity of the soils, the effluents are able to bring nitrogen into the local shallow groundwater and even into nearby canals, rivers, and coastal waters. Excess nitrogen feeds algae, reduces oxygen levels in water, and damages freshwater and coastal ecosystems. It also contributes to ongoing coastal issues like red tides and eutrophication. Florida is basically a coastal plain, a low-lying area where water can collect. The coastal regions are the most vulnerable. Rising sea levels, flooding, and storm surges can further allow the contaminated water to move around. Istratiy writes:

“Florida has taken steps to address water quality problems, but progress in upgrading outdated septic systems has been slow and uneven. Replacing old systems or connecting homes to sewer lines can be expensive, yet the cost of doing nothing continues to grow. Environmental damage, health risks and economic losses place a much heavier burden on communities over time.”

“Solving this problem will require coordinated action. State and local governments need to prioritize funding for septic-to-sewer conversions in the most vulnerable areas, improve maintenance and inspection requirements, and help homeowners manage the cost of necessary upgrades. Public awareness also plays a key role. When people understand how individual septic systems affect shared water resources, the issue becomes a matter of collective responsibility.”

     I have worked as a regulator and inspector in the past of household sewage treatment systems (ie, septic systems) in an area where it was common for some older systems and occasionally even some newer systems to fail. I know that for regular people, it becomes a significant economic issue. In modern times, it can be very expensive to replace a failing septic system, and it can even be financially inconvenient to pay to have it maintained and inspected. Thus, cost tends to slow down mitigation and replacement.

     In January 2025, Florida moved its onsite sewage program regulation and permitting for 16 counties from the County Health departments to the Department of Environmental Protection (DEP). Below is an update from the Florida DEP about the improved permitting and inspection numbers in the target counties.

     Researchers from Florida Atlantic University’s Harbor Branch Oceanographic Institute looked at water quality in southwest Florida, tracking microbes, and found that septic systems were a major contributor to water quality degradation. According to Florida Atlantic University:

“…there are about 39,768 “known” and about 57,054 “likely” septic systems in Southwest Florida’s Lee County (about 100,000 total). To identify sources of pollution contributing to the water quality woes, researchers examined septic system- groundwater- surface water couplings through the analysis of various parameters.”

      The researchers tracked microbes and nutrients and distinguished them into human and animal origins. Their research was published in September 2022 in the journal Science of the Total Environment. They utilized several tracers and indicators. One effective indicator for human waste was sucralose. The researchers found that human waste was definitely contributing to harmful algae blooms (HABs). One very important conclusion is that:

“Most (>80%) water table depth measurements were too shallow to support septic system functioning (<1.07 m).”

     This basically means that more than 80% of the septic systems in this region are basically dysfunctional, or what we used to call “failing.”

     The study showed that both groundwater and surface water were significantly contaminated with septic system waste, from both pathogens and nitrogen. Pathogens are indicated by fecal bacteria indicators like coliform bacteria.

     The researchers concluded:

“Urban water quality is complex because it is affected by myriad environmental, economic, and political issues. This means that resource managers must be able to identify sources contributing to water quality decline and then prioritize mitigation and abatement strategies. Due to the nature of human waste inputs (i.e., reactive nutrients, pathogens, bacteria, pharmaceuticals, etc.), improved wastewater infrastructure and management, including advanced wastewater treatment (nutrient removal), in …”

 

 

References:

 

Aging septic systems fuel Florida’s growing water quality crisis. Opinion by Iuliia Istratiy. Tampa Bay Times. February 2, 2026. Aging septic systems fuel Florida’s growing water quality crisis | Column

Water Quality Woes in S.W. Florida Linked to Seeping Septic Systems. Gisele Galoustian. Florida Atlantic University News Desk. August 9, 2022. FAU | Water Quality Woes in S.W. Florida Linked to Seeping Septic Systems

The Onsite Sewage Program has moved to the Florida Department of Environmental Protection. Florida Department of Health. 2025. Septic Systems - Florida Department of Health

Program Update - Phase I Transition. Division of Water Resource Management. Onsite Sewage Program. Florida Department of Environmental Protection. Program Update - Phase I Transition | Florida Department of Environmental Protection

Septic system–groundwater–surface water couplings in waterfront communities contribute to harmful algal blooms in Southwest Florida. Rachel A. Brewton, Lisa B. Kreiger, Kevin N. Tyre, Diana Baladi, Lynn E. Wilking, Laura W. Herren, and Brian E. Lapointe. Science of The Total Environment. Volume 837, 1 September 2022, 155319. Septic system–groundwater–surface water couplings in waterfront communities contribute to harmful algal blooms in Southwest Florida - ScienceDirect

Injecting Edited DNA and Growth-Promoting Bacteria into Pruned Plants Can Produce Gene-Edited and Transgenic Plants Faster

     A new breakthrough in plant biology is the enabling of a new technique to grow transgenic and gene-edited plants that can shorten the process from months to weeks. Normally, a single plant is grown and edited, and grows into a new plant, but it is sometimes not successful. The new technique involves injecting edited DNA and growth-promoting bacteria into a pruned plant. This takes advantage of a plant’s natural ability to regenerate when damaged. Thus, scientists can now begin with actual plant shoots rather than tissue culture. Cassidy Lovell of the Cool Down writes of the potential advantages of faster transgenic and gene-edited plants:

“This innovation could help farmers respond more rapidly to plant diseases or pests that threaten their yields. Invasive pests cause billions of dollars in damage each year, but gene-editing plants could make them more resistant, or even less desirable, to pests.”

“Environmentally, crops could be edited to better withstand rapidly changing climate conditions, like long heat waves or sudden cold snaps. They could even require less water or land, alleviating some strain on resources like water and soil.”

     Cell Press/Phys.org describes the process:

“By injecting bacteria carrying genetic instructions for wound healing and regeneration into a pruned plant's wound site, the researchers triggered the plant to grow new shoots, some of which were transgenic and gene edited.”

     The paper was published in the journal Molecular Plant.

"Plant regeneration has long been a major limitation in crop biotechnology," says senior author and plant genomicist Gunvant Patil of Texas Tech University.

"Our method leverages the plant's inherent regenerative capacity to rapidly produce gene-edited shoots, bypassing months of traditional tissue culture. This innovation has the potential to redefine how we create next-generation, improved crop varieties."    

"You decapitate the plant, you inoculate with Agrobacterium, and then the shoots that grow out of the wound will give rise to seeds that are transgenic or gene-edited," says co-author and plant genomicist Luis Herrera-Estrella of Texas Tech University.

"This technique could help us transform species that are usually very difficult to grow in tissue culture because it's faster and more natural."

     The researchers first tested the technique on tobacco plants, which regenerate readily. They achieved a 35% success rate. Next, they tried it on tomatoes, which are more difficult to regenerate. With tomatoes, they achieved a 21% success rate. The technique was initially unsuccessful in soybeans, which are notoriously difficult to regenerate. However, they were able to achieve success by changing the process a bit. Instead of applying Agrobacterium to pruned shoots, they applied the bacteria to soybean seeds that had been stimulated to germinate. Then they grew the soybeans in tissue culture for 3.5 weeks and were able to successfully grow transgenic shoots 28% of the time.

"With the conventional method, we need to grow soybeans in tissue culture for at least 3 to 4 months, so reducing that time to 3.5 weeks is a huge advancement," says Patil. "This is the first step, and we are now working to fine-tune this technology to apply it to more difficult crops, such as chickpeas, common bean, and many other crops."

     To reiterate, the major advancement of the new technique is the significant speed-up of the process for creating transgenic and gene-edited plants. This should enable the faster development of plants with desirable transgenic or gene-edited traits.

     

 

References:

 

Researchers make incredible breakthrough that could help protect food supply from major threat: 'Has the potential to redefine'. Cassidy Lovell. The Cool Down. February 1, 2026. Researchers make incredible breakthrough that could help protect food supply from major threat: 'Has the potential to redefine'

Growing transgenic plants in weeks instead of months by hijacking a plant's natural regeneration abilities. Cell Press. edited by Sadie Harley, reviewed by Robert Egan. Phys.org. November 6, 2025. Growing transgenic plants in weeks instead of months by hijacking a plant's natural regeneration abilities

A synthetic transcription cascade enables direct in planta shoot regeneration for transgenesis and gene editing in multiple plants. Arjun Ojha Kshetry, Kaushik Ghose, Anshu Alok, Vikas Devkar, Vidhyavathi Raman, Robert M. Stupar, Luis Herrera-Estrella, Feng Zhang, and Gunvant B. Patil. Molecular Plant. Volume 18, Issue 12. p2066-2081. December 1, 2025. A synthetic transcription cascade enables direct in planta shoot regeneration for transgenesis and gene editing in multiple plants: Molecular Plant

 

Clean Energy Advocates are Irresponsibly Putting Grid Reliability at Risk by Opposing Fossil Fuel Power According to NERC

       With power demand rising for the first time in a few decades, there is a clear need to prevent power grids from losing reliability, according to the North American Electric Reliability Corporation (NERC). Demands from clean energy advocates are exacerbating the issue. I know that during this unprecedented extended interval of very cold weather, I am grateful that the power has remained on and able to keep warm enough. An article by Everett Sloane in Morning Overview notes that retiring fossil fuel plants too soon could result in reliability events that could lead to rolling blackouts. Energy Secretary Chris Wright, who has delayed some of these planned retirements, no doubt agrees.

“Regulators are effectively telling policymakers that the physics of the system are changing faster than the infrastructure, and that without a course correction, reliability risks will spread from a handful of stressed regions to much of the continent.”

     The simple math of it is that demand is up and firm capacity, or dependable power generation, is down. Data centers, industrial loads, and electrified technologies are expected to make and keep peak demand very high.

     NERC’s Long Term Reliability Assessment (LTRA) calculates that 21 GW of fossil fuel generation capacity will be lost over the next decade. Since that is in capacity and plants scheduled for retirement are often already running at low utilization rates (capacity factors), that is not as bad as it seems. However, it does represent a significant loss of firm capacity.

“The National Rural Electric Cooperative Association, or NRECA, has issued a call for swift action to address what it describes as a worsening grid reliability outlook, warning that projected energy resource and transmission growth will not keep up with demand in parts of the Midwest, Mid Atlantic, and Northwest. In its statement, NRECA warns that these regions could face heightened risk of shortfalls if dispatchable plants close before new capacity and transmission lines are in place, a concern that dovetails with NERC’s broader warning that much of the grid is drifting into a more fragile state.”

     It should perhaps be pointed out that the impressive levels of fossil fuel, mainly coal and old inefficient gas plants, retirements of the past were easier to accommodate since power demand had been steady. That is no longer the case.

     The Morning Overview article notes that Winter Storm Fern will be a major stress test, and the data that arises from it should help with evaluating reliability concerns. As can be seen below, the first few days of this storm and especially the extended cold spell resulted in ISO New England turning, as they have now for years, to fuel oil, as can be seen in the graph below from the EIA. Oil made up the majority of power in the region. This fuel oil is much more expensive than natural gas, puts out far more air pollutants than natural gas, and also emits more CO2 than natural gas. Years or decades of burning oil every time a cold snap hits is not the most responsible way to address such cold snaps, which are guaranteed to happen. Building natural gas pipelines to nearby inexpensive natural gas sources makes much more sense, but is nonetheless unlikely to happen on a scale big enough to make a difference.

     One thing is for certain. We need enough dispatchable generation to cover such events effectively.

“Industry groups are pushing for a slower pace of retirements, while clean energy advocates argue that the answer lies in accelerating investment in transmission, storage, and flexible demand rather than extending the life of aging coal units. NERC’s data, including the projected 21 gigawatt decline in fossil capacity and the 24 percent rise in peak demand, suggest that both sides are grappling with the same constraint: time. To avoid the scenario where huge chunks of the grid become vulnerable, policymakers will need to align permitting, market design, and reliability standards so that new resources are in place before old ones exit, rather than after the fact.”

     According to Utility Dive’s Robert Walton, NERC’s assessment has most of the demand increase coming from data centers. However, summer demand is also expected to rise considerably, although winter demand is expected to rise a little more than that.

“Summer peak demand across the bulk system is forecast to grow by 224 GW over the next 10 years, a more than 69% increase over the 2024 LTRA forecast and a 24% increase from 2025 peak demand.”

“Winter demand growth is even higher, with 246 GW of growth forecast over the next decade.”

     MISO, PJM, ERCOT, and the Pacific Northwest are expected to lead demand growth. John Moura, NERC’s director of reliability assessments and performance analysis, noted that the future has never been more uncertain. Another NERC official noted that delays in connecting new resources and unanticipated generator retirements resulted in bulk system capacity being less than projected for the past two years in a row. They also note that solar and battery additions can be effective for addressing summer demand but not winter demand.

     The Electric Power Supply Association (EPSA) noted that both new resources and plant retirement delays will be needed to ensure reliability.

“Reliability is best served by competitive electricity markets that send clear, durable development signals — not by policy interventions that create misalignment between supply and demand,” EPSA President and CEO Todd Snitchler said in a statement. “In order to address the warnings NERC’s LTRA sets out, it will require getting market signals right while addressing permitting and siting delays, supply chain bottlenecks, and other barriers to development.”

 

 

References:

 

Regulator warns huge chunks of grid could fail as fossil fuels vanish. Everett Sloane. Morning Overview. January 31, 2026. Regulator warns huge chunks of grid could fail as fossil fuels vanish

NERC forecasts peak demand to rise 24% on new data center loads. Robert Walton. Utility Dive. January 30, 2026. NERC forecasts peak demand to rise 24% on new data center loads | Utility Dive

Hot Water from CERN’s Large Hadron Collider Cooling System is Now Being Used to Heat Local Homes and Businesses in France

      The European Organization for Nuclear Research, known as CERN, is now utilizing waste heat from the cooling system of its particle accelerator, known as the Large Hadron Collider (LHC), to heat local homes and businesses in France. Heat recovered from the LHC has been supplying a heating network for a residential and commercial area in the nearby French town of Ferney-Voltaire since mid-January. It is expected to supply heat for the equivalent of several thousand homes.

     The LHC is 27 km in overall length with eight surface points, one of which is near Ferney-Voltaire. The cooling water that cools the equipment heats up, and instead of using cooling towers to cool the water and then release it to the atmosphere, now the hot water initially passes through two 5-MW heat exchangers, which transfer thermal energy to the new heating network in Ferney-Voltaire. 

     Right now, only one heat exchanger is in use, and in the summer of 2026, the LHC will be shut down for a multi-year maintenance and upgrade period. However, cooling water will still be needed, and between 1 and 5MW will be supplied to the heating network during the log shutdown. After the upgrades are compete both 5MW heat exchangers will be operational, potentially doubling the heat output. According to CERN:

“Other projects include CERN’s Prévessin Data Centre, inaugurated in 2024, which is equipped with a heat-recovery system set to warm most site buildings from winter 2026/2027, and the future recovery of heat from LHC Point 1 cooling towers to supply buildings on CERN’s Meyrin site. Together, these initiatives will save 25–30 GWh per year as of 2027, marking significant progress in CERN’s responsible energy management.”

       In Ferney-Voltaire, the recovered waste heat is fed directly into the town’s district heating network.

References:

Heating homes with the world’s largest particle accelerator. Now operational, a new heat exchange system is reusing hot water from part of the Large Hadron Collider’s cooling system to heat homes and businesses in the local area. Kate Kahle & Anna Cook. CERN. January 28, 2026. Heating homes with the world’s largest particle accelerator | CERN

CERN. Wikipedia. CERN - Wikipedia

World’s most powerful particle collider supplies heat to thousands of French households. Georgina Jedikovska. Interesting Engineering. January 29, 2026. World’s most powerful particle collider supplies heat to thousands of French households

 

China is Producing More Natural Gas and is Set to Become World’s Third Largest Producer

      There is a fracking boom going on in China. Shale gas is leading it. The demand for gas is there, and the reserves are there. An article in the Telegraph by Hans van Leeuwen notes that China’s natural gas production hit a record high last year, rising 6% to 262 billion cubic meters (BCM), about 9.17 TCF, or 25.1 BCF per day. Current trajectories suggest that China will overtake Iran as the world’s third-largest producer of natural gas sometime this year. President Xi declared he wants China to produce 300 BCM annually by 2030. Demand for natural gas is very high in China, and the country imports about 40% of its gas. China is the world’s largest LNG importer, so producing more gas domestically could save it lots of money. Much of China’s imports come via pipeline from Russia, which also sells LNG to China. They also buy LNG from Australia, Qatar, and Malaysia. China was buying U.S. LNG, but the Trump tariffs have halted that trade. Perhaps this is contributing to the increasing trade deficit the U.S. is facing as a whole, which is the opposite effect desired by the tariff actions.

     It has been noted that China’s shale geology is more challenging than that in the U.S. However, the reserves are huge. China has 1,100 TCF of estimated shale gas reserves, compared with 600 TCF in the US, according to the article. The economically recoverable portion, however, may be considerably lower. China began fracking for shale gas in 2012, and since 201,7 shale gas production has grown by 20% per year.

     China has been offering tax breaks and subsidies for state-owned energy giants CNPC and Sinopec. Even if Xi’s 2030 goals of producing 300 BCM are reached, China will still be a net importer by a wide margin, as 2030 natural gas demand is expected to reach 550 BCM.

     He also points out that natural gas supplies just 9% of China’s total energy demand, although the country hopes to grow its share of natural gas for power, heating, and industry. While China may move into third place for gas production, it currently produces much less than half of what Russia produces and not much over a quarter of what the U.S. produces.

    

 

References:

 

 China unleashes fracking boom to ramp up gas supplies. Hans van Leeuwen. The Telegraph. January 29, 2026. China unleashes fracking boom to ramp up gas supplies

China’s Great Green Wall Reforestation Initiative Has Dramatically Altered Local Hydrologic Cycles in Various Ways and Places

     Reforestation at a significant enough scale changes weather and precipitation patterns. A new paper published in the journal Earth’s Future shows that China’s Great Green Wall initiative of planting billions of trees over the past couple of decades has significantly changed local and regional weather and precipitation patterns and evapotranspiration rates. Planting more trees to induce more rainfall is known as reforestation rainfall. In general, deforestation reduces rainfall, and reforestation increases it.

     New research published in the journal Earth’s Future shows that the country’s reforestation effort to slow land degradation and fight climate change has also reshaped its water supply and local hydrologic cycles “in surprising, and sometimes uneven, ways.” More specifically, it changed evapotranspiration rates, which led to changes in water cycles. Evapotranspiration is simply the release of moisture from leaves to the atmosphere.

     Northern China is arid, and previous deforestation has led to increases in desertification. The Great Green Wall has been deemed successful in slowing desertification. The paper studies the period from 2001 to 2020, the period when many of the trees were planted, although reforestation projects began there in the 1990s. What was perhaps unexpected was where the precipitation changes occurred. Meteorologist Jennifer Gray writes:

“…between 2001 and 2020, freshwater availability dropped in China’s eastern monsoon region and northwestern arid region, but increased over the Tibetan Plateau.”

“Trees can grab water from much deeper into the earth, and so it’s going to release all of that moisture into the atmosphere, even in places where it is not raining,” Gray said.

“The atmosphere and the winds can actually transport moisture more than 4,000 miles,” Gray explained. “So if you plant trees in one area that doesn’t mean that that’s exactly where it’s going to rain.”

     The water was distributed unevenly, and some places actually got drier.

“While re-greening an area has tremendous amounts of benefits for the environment and the entire planet, it’s the local people that actually are going to see the consequences, whether that’s pro or con,” Gray said.

     Gray also noted that the study is both encouraging and cautionary.

     According to an article for Petsnpals by Julie Majid:

“Stretching from Xinjiang through Inner Mongolia to Heilongjiang, the Three North Shelterbelt Project reshaped millions of hectares. Entire counties converted open land into forest belts meant to block wind and trap soil. The scale was continental.”

“Farmers noticed changes before statisticians did. Rains came later, sometimes heavier, sometimes missing critical planting windows. The problem was not drought everywhere, but unpredictability.”

“Climate data from northern China showed altered seasonal rainfall distribution. Summer precipitation clustered into fewer, more intense events in some regions, while spring rains weakened. These shifts became clearer as forest cover expanded, as reported by Science, complicating long standing assumptions about land and sky behaving independently.”

“Deep soil layers showed long term drying beneath forests. Trees accessed water faster than recharge could replace it. Over time, reduced soil moisture limited later evaporation, shifting when and where rain could form. The land looked restored, but its hydrology had fundamentally changed.”

     Planting trees with large water demands can deplete soil moisture. Thus, species selection is an important part of optimizing the process and mitigating problems. Planting trees with high water demands can deplete groundwater as it can exceed recharge rates, eventually affecting local water wells.

     Another risk noted is that reforestation can change monsoon patterns, which can potentially have drastic effects on rainfall patterns. Another effect was the reduction of airborne dust, which is most beneficial. However, dust can affect cloud formation, so its decrease could lead to less rain in some areas. She sees reforestation as a way of manipulating the climate, which I would call geoengineering. Models and simulations should be adjusted based on the new data provided by the study. In addition, she gives some recommendations:

“Future projects may need different species mixes, lower planting density in water limited zones, and tighter monitoring of moisture budgets. Restoration will likely succeed best when forestry, hydrology, and meteorology plan together, because rainfall is not just something forests receive, it is something forests can influence.”

     The study compares natural forests and planted forests across China. It uses the metrics of hydraulic safety and hydraulic efficiency. 

     The study concluded that, in general, planted forests had higher hydraulic safety but lower hydraulic efficiency. However, several other variables could change that relationship on the local level.

     This is an important study that can be a guide for other reforestation impact studies in the future.

      

 

References:

 

China planted billions of trees ... and accidentally moved its rain. Jenn Jordan. The Weather Channel. January 21, 2026. China planted billions of trees ... and accidentally moved its rain

Weather Words: Reforestation Rainfall: Reforestation rainfall refers to the phenomenon where planting more trees can lead to more rainfall. Jennifer Gray. The Weather Channel. April 24, 2025. Weather Words: Reforestation Rainfall | Weather.com

Climate-Driven Hydraulic Traits Shift in Natural and Planted Forests: Patterns, Drivers, and Future Acclimation. Yan Bai, Yujie Hu, Yanlan Liu, Kailiang Yu, Xiangzhong Luo, Liyao Yu, Lei Tian, and Jianping Huang. Earth’s Future. Volume14, Issue1. January 2026. Climate‐Driven Hydraulic Traits Shift in Natural and Planted Forests: Patterns, Drivers, and Future Acclimation - Bai - 2026 - Earth's Future - Wiley Online Library

China accidentally altered its rainfall after planting billions of trees. Julie Majid. Pets n Pals. January 29, 2026. China accidentally altered its rainfall after planting billions of trees

Fluvial Geomorphology and Dam Failure Analysis Utilizing NASA’s Surface Water and Ocean Topography (SWOT) Satellite

     NASA launched the Surface Water and Ocean Topography (SWOT) satellite in 2022. The satellite is being used to determine the height and extent of bodies of water and how they shape the land. This can be a new way to do fluvial (river) geomorphology. Phys.org writes:

“In the past, fluvial geomorphologists relied on airborne surveys or fieldwork in which they carefully studied a single location. Researchers would map out river cross sections to estimate things like how much sediment a river can carry away and how likely a river is to flood in different conditions.”

     Virginia Tech geoscientists demonstrated that the satellite can be used for fluvial morphology.

"SWOT allows us to cover all the rivers in the world and understand how they're evolving," said Stroud. "It really transforms the scale at which we can study rivers."

     Three applications include the study of large river dynamics, sharp breaks and slopes along a river, such as waterfalls, and shear stress, which helps scientists to understand how much sediment water pushes along.

     The researchers also demonstrated that SWOT can be used to observe and track dam failures. Aging infrastructure and flooding are often the causes of dam failures.

     SWOT includes an interferometric synthetic aperture radar (inSAR) instrument. InSAR has proven useful for measuring even very small land movements.

     Satellite remote sensing has long been applied to the study of fluvial geomorphology. More recently, it has been applied to study river systems at large scales, something traditional fluvial geomorphology methods can’t do. A paper, published in the Geological Society of America’s GSA Today, explains the advantages:

“The Surface Water and Ocean Topography (SWOT) satellite, launched in December 2022, has the potential to transform the field of fluvial geomorphology by providing new data that are unlike what past satellite missions have offered. SWOT produces high-precision images of surface water topography, enabling a new suite of analyses in fluvial geomorphology. SWOT was primarily designed for oceanography and inland hydrology applications and uses a Ka-band synthetic aperture radar to provide simultaneous measurements of both the elevation and extent of surface water over two 50-km-wide swaths (Fu et al., 2024). These same observations can also be readily utilized for fluvial geomorphology applications. The measured water surface elevation (WSE) is an important geomorphic variable in itself, and it can be used to estimate other variables including river slope and river discharge, both of which are related to sediment transport processes (Wolman and Miller, 1960; Bagnold, 1966; Howard et al., 1994).”

     These new methods complement other techniques such as light detection and ranging (LiDAR). Data can be presented in three formats: vector, raster, and pixel cloud (a point cloud of water mask pixels).

     The paper goes on to show how SWOT can be used to study large river dynamics, bed shear stress, and knick points. Large river systems are more complex and harder to study.

“…they often have greater internal complexity, more anabranching, and a wider range of channel planforms (Ashworth and Lewin, 2012). These complexities can make predicting their geomorphic behavior difficult, and much work has been dedicated to modeling and quantifying the morphology of large and braided rivers (Williams et al., 2016).”

     Below is a SWOT analysis of the Yukon River in Alaska.

     Channel bed shear stress, a fundamental measure of a river’s ability to move bed material, can be used to study sediment transport.

“Figure 3 shows an example of shear stress calculations along the Klamath River in northern California using the SWOT RiverSP node product. The Klamath River is currently a site of great interest due to the ongoing removal of a series of dams along its upper reaches.”

     Knickpoints are abrupt increases in downstream slope along a channel profile, such as at a waterfall. Knickpoints in streams migrate, and SWOT can be used to better measure migration rates. Dam removals and other landscape and water changes can create new knickpoints. SWOT can be used to predict knickpoint migration after dam removals.

“Forecasting the effects of dam removal (or failure) is challenging, but new data from SWOT will allow us to study the postevent knickpoint migration and channel morphology change, improving our understanding of the geomorphic effects of dam removal (Pizzuto, 2002). Additionally, we now have the capability to directly observe and measure knickpoint and knick-zone migration rates at a global scale and at regular temporal intervals.”

     Below is an analysis of the Rapidan Dam on the Blue Earth River in Minnesota, before and after dam removal.

     The authors think that SWOT will be used for other fluvial geomorphology applications as well and lead to more accurate databases of river dynamics. The geomorphic impacts of floods can be studied with SWOT as well. The long-term effects of both dam construction and dam removal using the satellite can be determined more accurately than before. SWOT data can also be used to improve modeling and simulations.  

 

 

   

References:

 

Geoscientists use satellite data to determine how water shapes the land. Kelly Izlar. Phys.org. January 19, 2026. Geoscientists use satellite data to determine how water shapes the land

SWOT Satellite: A New Tool for Fluvial Geomorphology. Molly Stroud, George H. Allen, J. Toby Minear. Julia Cisneros, and Laurence C. Smith. Geological Society of America. GSA Today. Volume 35 Issue 12 (December 2025). SWOT Satellite: A New Tool for Fluvial Geomorphology

 

 

Quantifying Denitrification Rates in Rivers and Streams: Study Shows Rates Differed in Streams, Compared to Rivers

     Human activities like crop agriculture, livestock agriculture, and inadequate sewage treatment add nitrogen to streams and rivers. Part of it travels down the streams into rivers and ends up in the ocean. Another portion of it is removed in a natural chemical process known as denitrification. The University of Missouri explains the process:

“Soil microorganisms need oxygen for fuel. When the soil is very wet, water fills in the spaces between soil particles. This leaves very little room for oxygen. Some soil microorganisms can get the oxygen they need from the oxygen portion of the nitrite (NO2-) and nitrate (NO3-) forms of nitrogen. When this happens, nitrogen (N2) and nitrous oxide (N2O) gas are formed. These gases return to the atmosphere, and there is a net cycle in the soil. This is called denitrification.”

Two main factors influence denitrification:

·        The oxygen supply in the soil.

·        The soil microorganisms.

     Factors that influence the rates of denitrification include the amount of organic matter, soil water content, soil oxygen supply, soil temperature, soil nitrate levels, and soil pH. Rates are higher in waterlogged soils. Denitrification can have both positive and negative impacts on water quality. When nitrites and nitrates are converted to nitrogen and nitrous oxide gases, there is an improvement in water quality. However, waterlogged soil can lead to water rich in nitrites and nitrates percolating downward into groundwater aquifers, negatively impacting water quality. Groundwater contamination is most likely where the depth to groundwater is shallow, and the soil is sandy and permeable. Nitrates are particularly dangerous for infants, including animal babies.

     Scientists agree that we need better quantification of streams and rivers, especially rivers. A new study and paper in the Journal of Geophysical Research: Biogeosciences set out to do this. According to Phys.org:

“The researchers took hourly water samples from the Tippecanoe River and the Shatto Ditch in Indiana over 36-hour periods in spring, summer, and fall. They used open-channel metabolism and a membrane inlet mass spectrometry–based model to study how rates of denitrification fluctuated in both waterways as the seasons changed.”

     Their results showed that the stream had higher denitrification rates per square meter than the river in all three seasons. They attributed this finding to the higher nitrate levels in the stream and the higher microbial activity in the stream.

“However, when the researchers scaled up, the denitrification rate in rivers per kilometer of channel length was equal to or even higher than that of streams.”

     The higher seasonal nitrate levels were likely caused by higher fertilizer application rates in spring and early summer. Precipitation levels were also higher in these seasons. In contrast, denitrification rates were the highest for rivers in the fall. They attribute this to higher rates of ecosystem respiration in the fall.  

     As shown below, oxygen and nitrogen levels were determined from oxygen/argon ratios and nitrogen/argon ratios, respectively.

 

References:

 

Denitrification looks different in rivers versus streams. Nathaniel Scharping. Phys.org. January 19, 2026. Denitrification looks different in rivers versus streams

Fluvial Denitrification Rates in an Agricultural River and Its Tributary Vary Due To Size and Season. Abagael N. Pruitt, Jennifer L. Tank, Shannon L. Speir, and Alexander J. Reisinger. October 29, 2025. JGR Biogeosciences. Volume130, Issue11. November 2025. Fluvial Denitrification Rates in an Agricultural River and Its Tributary Vary Due To Size and Season - Pruitt - 2025 - Journal of Geophysical Research: Biogeosciences - Wiley Online Library.

Nitrogen in the Environment: Denitrification. Extension. University of Missouri. November 2022. Nitrogen in the Environment: Denitrification | MU Extension