nitrogen

Thanking America’s Sustainable Farmers

By Christina Badaracco

While working on education and outreach in EPA’s Office of Wetlands, Ocean, and Watersheds, I have been particularly inspired by our work with agriculture. As an environmentalist and a foodie, I love learning about the connection between healthy food and sustainable agriculture, and I am always eagerly looking to share that information with the public. This is why I’m excited about our efforts to interview and feature for the American public “farmer heroes,” who manage the nitrogen and phosphorus pollution on their farms and grow America’s food supply in a sustainable manner.

Through our “Farmer Hero” campaign, and through my own personal purchasing decisions as an informed consumer, I am supporting farmers who protect local land and water resources while undertaking the critical role of producing America’s food supply.

I was first exposed to the world of sustainable farming in college, and have since been inspired by the videos and writing of Joel Salatin, owner of Polyface Farm in Swoope, Virginia and a leader in the local food movement. I had the pleasure of visiting his farm last fall, and seeing the clever contraptions (e.g., the Eggmobile and Gobbledygo) and beautiful scenery I had read about in his books. Views of dirt-covered pigs, running around in the woods; ripe red tomatoes, grown without chemicals; and the engaging storytelling of our host were a treat and well worth the drive out from D.C.

In late May, I was thrilled to return to the area to meet other farmers who practice sustainable agriculture. I visited Robert Schreiber of Bell’s Lane Farm, and saw his on-farm composting operations and sales. I also met Gerald Garber from Cave View Farms, and learned how his livestock fencing and no-till farming reduce pollution runoff.

It is a delight to meet these farmers who have offered to share their stories: their goals for their properties and families, their innovative approaches for managing nutrients, and above all, their willingness to protect their local environment and the many lands downstream (http://www2.epa.gov/nutrientpollution/farmer-heroes-manage-nutrients-farm). I am encouraged to see EPA building better relationships with farmers to protect the same land, water, and food on which we all rely.

To Mr. Salatin and the other farmers who read this blog; who are conserving their resources, protecting their local waterways, and raising their animals and crops sustainably; and whom I one day hope to meet, we thank you. You are our heroes.

About the author: Christina Badaracco has worked in EPA’s Office of Wetlands, Oceans, and Watersheds since 2012. She works on communication and outreach projects regarding nutrient pollution, and is particularly interested in sustainable agriculture.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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Wetlands: Earth’s Kidneys

By Marguerite Huber

Stream restoration research

Stream restoration research

Our organs are vital to our health, with each one playing a significant part. Kidneys, for instance, filter our blood to remove waste and fluid. Wetlands are often referred to as “Earth’s kidneys” because they provide the same functions, absorbing wastes such as nitrogen and phosphorous. When excess amounts of these substances—nutrient loading—flow into waterways it can mean harmful algal blooms, hypoxia, and summer fish kills.

Recognizing the importance of wetlands, many communities are taking steps to protect, restore, and even create wetlands.

For example, many stream restoration projects include constructing wetlands to absorb stormwater runoff and absorb excess nutrients and other pollutants that flow in from a host of sources across the watershed (known collectively as nonpoint source pollutants).

These constructed wetlands can provide key elements to urban stormwater management because they help reduce the impacts of runoff after a rainstorm or big snowmelt event. Such runoff typically transports high concentrations of nitrogen and phosphorous and suspended solids from road surfaces into waterways.

One such type of wetland that may provide these kinds of benefits is the oxbow lake, so named because of their curved shape. These form naturally when a wide bend in a stream gets cut off from the main channel, but EPA researchers are taking advantage of a couple of oxbow wetlands created during stream restoration activities at Minebank Run, an urban stream in Baltimore County, MD.

The researchers are studying the oxbow wetlands to quantify how effective such artificially created wetlands are at absorbing nitrogen and phosphorous in an urban setting. If these types of wetlands are effective, then deliberately constructing oxbow wetlands could be an important nutrient management strategy in such landscapes.

From May 2008 through June 2009, the researchers analyzed water, nitrate (a form of nitrogen pollution), and phosphate flow during four storms to better understand the impacts of hydrology on the potential for the two oxbow wetlands and the adjacent restored streambed to absorb or release nutrients.

The results suggest that oxbow wetlands in urban watersheds have the potential to be “sinks” that absorb and store nitrogen. They also reinforced information pointing to the dynamic hydrologic connection linking water and nutrient flow between streams and nearby oxbow wetlands, findings that if confirmed through further investigation can be used to improve restoration efforts that improve water quality across entire watersheds.

When it comes to phosphorus, the researchers found that oxbows don’t function as “sinks,” but “sources,” that contribute a net increase of the nutrient. They hypothesize that this is because the nutrient is released from wetland sediments during storms or other similar events. Future studies are needed to investigate the magnitude of phosphorous release, and how important that contribution is across the watershed.

Just like how our kidneys are an essential aspect of the human body, wetlands are an important aspect of nature. Retaining additional nutrients and treating non-point source pollutants help give natural and constructed wetlands the affectionate nickname of “Earth’s Kidneys.”

About the Author: Marguerite Huber is a Student Contractor with EPA’s Science Communications Team.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Nutrient Management: Always on My Mind

By James R. Mihelcic, PhD, BCEEM

EPA-grantee and guest blogger James R. Mihelcic

EPA-grantee and guest blogger James R. Mihelcic

I am inspired to solve the complex problem of nutrient (nitrogen and phosphorus) management every day.  I think about solving this problem when I tend my winter garden of lettuce and peppers, around my neighborhood as I watch stormwater race from lawns to the Hillsborough River, in the classroom, and when I spend time outdoors enjoying our nation’s waters.

And I am in good company with my thoughts. You see, the National Academy of Engineering has identified managing the nitrogen cycle as one of their Grand Challenges.

I even started my New Year by canoeing in the Chassahowitzka National Wildlife Refuge and got to thinking about nutrients.  This was because some of the springs that feed the refuge have developed the tell-tale signs of nutrient pollution (green, slimy-looking plant growth) from on-site wastewater generation and lawn runoff from surrounding homes.  On that day we were also welcomed into the winter home of a group of manatees.  Manatees depend on sea grass for survival, and excessive nutrients cloud coastal waters, preventing sea grass growth. 

With support from an EPA Science to Achieve Results (STAR) grant, we established our Center for Reinventing Aging Infrastructure for Nutrient Management, which is transforming my daily thinking to everyday reality.  We are reimagining aging coastal urban infrastructure systems to consider nutrient recovery and management that contribute to sustainable and healthy communities.

Manatee at a U.S. Wildlife Refuge, Florida. Image courtesy of U.S. Fish and Wildlife Service.

Manatee at a U.S. Wildlife Refuge, Florida. Image courtesy of U.S. Fish and Wildlife Service.

I have great expectations for our Center research and demonstrations.  Our goals are to develop the science behind new technology and management innovations, and to develop a deep understanding of integrated systems.  We will demonstrate and assess innovations to provide new knowledge for students, community members, practitioners, and other stakeholders.

We are even transforming how we educate new engineers. For example, our new textbook, Environmental Engineering: Fundamentals, Sustainability, Design integrates sustainability and nutrient concepts into every chapter, and has the potential to reach over 10,000 undergraduate engineers every year.

Our research will benefit the public because poor water quality lowers the economic, social, and environmental value of our nation’s waters for current and future generations. 

In Florida, our springs, rivers, estuaries, coastal waters, and the Everglades all suffer because of nutrient pollution.  We have already come up with some ways to help manage nutrient pollution while also meeting the agricultural needs to provide national and global food security. For example, we have shown that 22% of the global demand for phosphorus could be met if we just recovered this valuable resource from domestic wastewater. We’ve also shown how wastewater infrastructure that serves a rapidly urbanizing world can be integrated with recovery of valuable water and nutrients to improve food security.

You can see why nutrients are always on my mind.  I hope they are now on yours.

About the author: EPA-grantee and guest blogger James R. Mihelcic is a Professor of Civil & Environmental Engineering and State of Florida 21st Century World Class Scholar at the University of South Florida (Tampa), where he directs the Center for Reinventing Aging Infrastructure for Nutrient Management

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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SPARROWs, Lakes, and Nutrients?

By Jeff Hollister

Dock extending into a lake with forested background.Based on the title above, you probably think I don’t know what I am talking about. I mean really, what do sparrows, lakes, and nutrients have in common? In this case, a lot. So much so, an inter-agency team of EPA researchers in Narragansett RI, and a colleague from the U.S. Geological Survey (USGS) in New Hampshire have been working together to better understand how these three seemingly disparate concepts can be linked together. Some of the results of this work are outlined in a recent publication in the Open Access journal, PLos One

The sparrow I am referring to isn’t small and feathered, it is a model developed and refined by the USGS. Since the late 1990’s, USGS has been developing SPARROW models which have been widely used to understand and predict the total amount of nutrients (among other materials) that streams are exposed to over the long-term. This is known as “nutrient load.” The models are important because they provide a picture over a very large extent of where nutrients might be relatively high.

However, when it comes to lakes, SPARROW doesn’t directly provide the information we need. For our research on lakes, we need reasonable estimates of the quantity of nutrients in a given volume of water (i.e., nitrogen and phosphorus concentration), not long term nutrient load for the year. This is important, because the higher the nutrient concentrations at any given time, the greater the chance of triggering algal blooms—and more blooms mean a greater probability of toxins released by algae reaching unhealthy levels.

In order to better estimate the nutrient concentrations, we needed to use the SPARROW model for total load, but also account for the differences between load and concentration. Our solution: combining field data, data on lake volume and the SPARROW Model.

In our paper “Estimating Summer Nutrient Concentrations in Northeastern Lakes from SPARROW Load Predictions and Modeled Lake Depth and Volume,” recently published in PLoS One, we describe how we combined modeling information from SPARROW, summertime nutrient concentrations collected during EPA’s 2007 National Lakes Assessment, and estimated lake volume (see this and this for more).

The end result of this effort is better predictions, by an average of 18.7% and 19.0% for nitrogen and phosphorus, respectively.

What is the meaning of this in terms of our environment, and importantly, the potential human health impacts? If we are able to better predict concentrations of nutrients it will hopefully also improve our ability to know where and when we might expect to see harmful algal blooms, specifically harmful cyanobacterial algal blooms. Cyanobacteria have been associated with many human health issues, from gastro-intestinal problems, to skin rash, and even a hypothesized association with Lou Gehrig’s Disease (for example, see this). So, in short, better predictions of nutrients, will, in the long run, improve our understanding of cyanobacteria and hopefully reduce the public’s exposure to a potential threat to health.

About the author: Jeff Hollister, a co-author on the study outlined in this blog post, is a research ecologist with an interest in landscape ecology, Geographic Information Systems (GIS), the statistical language R, and open science. The focus of Jeff’s work is to develop computational and statistics tools to help with the cyanobacteria groups research efforts. Jeff is also an outspoken advocate for open science and open access among his colleagues.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Climate Change, Nitrogen and Biological Diversity

By Chris Clark, Ph.D.

When I visit our national parks, hike in the woods or backpack in the mountains, one of the things I enjoy most is the natural beauty that surrounds me—especially the plants. I’m a plant person, which is hard for some people to understand. (“They don’t do anything” many of my friends quip.) But, to me, that couldn’t be further from the truth.

Prairie scene

Three of the most prevalent dangers to plant biodiversity are habitat loss, climate change and nitrogen deposition.

Plants form the foundation for all robust ecosystems, supporting healthy biogeochemical cycles (how materials—for example, fallen leaves—move through systems and are chemically altered by both biological and geological forces), clean air and water, and all higher life forms. To me, this gives plants a quiet kind of majesty that is beautiful to witness.

All the different types of plant species in an ecosystem, from the largest trees to the tiniest wildflowers, play a role in the healthy functioning of that system. In the systems that I studied as a graduate student, the grasslands of Minnesota, it blew me away how many different species co-existed in one square meter of space. What once was just “green grass” became a teeming system of life to me.

Three of the most prevalent dangers to plant biodiversity nationwide are habitat loss, climate change and nitrogen deposition. These stressors can lead to changes that may reduce plant biodiversity, which can cascade through systems and affect other processes and services.

The work I do at EPA is important because it can help preserve ecosystems. I look at different stressors, like climate change and nitrogen deposition, and their impacts on ecosystems. I identify the types of changes that occur and the rate at which the changes are happening. If we understand this, we will be better poised to support and inform policy decisions that enhance the sustainability of our natural resources and avoid irrevocable damages.

For a recent project, I looked at how nitrogen deposition impacts plant biodiversity on land nationwide.  My collaborators and I examined “critical loads” (the upper limit of nitrogen an ecosystem can handle) from different regions of the U.S.  We then used computer modeling to estimate when deposition was too high and what the effect might be.

The results showed that many regions had nitrogen deposition amounts that may be too high, with losses of species ranging from one to 30 percent using a “worst-case scenario” approach.  When we used a “best-case scenario” approach, we estimated minimal losses. We had to use both of these scenarios because scientists don’t know exactly where in this range the critical loads are, and for which systems.

Before our study, no one knew what the ramifications could be of such a range. Refining these estimates of critical load thus is a very important area of future research.

Our results were recently published in the journal Ecology. Future work will build on this project to look at different aspects of the climate change-nitrogen relationship.  As a whole, the research will help promote a better understanding of how climate change and nitrogen deposition may impact our natural environment; this, in turn, will help policy makers mitigate these impacts. That’s important to me, and probably to anyone, who enjoys walking in the woods, backpacking or any other outdoor activity.

About the Author: EPA research scientist Chris Clark, Ph.D., works on a diversity of issues related to climate change, including biodiversity, biofuels, and urban resilience.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Challenging Nutrients: EPA and Partners Launch New Ideation Prize

Effects from excess nutrients in American waterways cost the country more than $2 billion each year.

Activities of daily modern life add small amounts of the nutrients nitrogen and phosphorus to our lakes, rivers and estuaries, either directly or indirectly.

We all contribute to the widespread problem. Runoff from our suburban lawns, city streets and rural fields is just one of many ways we introduce more nutrients into the environment.

The partnership for this challenge currently includes: - White House Office of Science and Technology Policy - U.S. Environmental Protection Agency - U.S. Department of Agriculture - National Oceanic and Atmospheric Administration  - U.S. Geological Survey - Tulane University - Everglades Foundation

The partnership for this challenge currently includes:
– White House Office of Science and Technology Policy
– U.S. Environmental Protection Agency
– U.S. Department of Agriculture
– National Oceanic and Atmospheric Administration
– U.S. Geological Survey
– Tulane University
– Everglades Foundation

These excess nutrients end up in our waterways and fuel algae growth that exceeds healthy ecosystem limits. In turn, algal blooms can contaminate drinking water, kill aquatic species and negatively affect water-based recreation and tourism.

A partnership of federal agencies and stakeholders has announced a new prize competition to collect innovative ideas for addressing nutrient overloads.

The challenge aims to identify next-generation solutions from across the world that can help with excess nutrient reduction, mediation and elimination. The total payout will be $15,000, with no award smaller than $5,000. Proposals can range from completely developed ideas to exploratory research projects.

Ideas will be judged on a range of criteria, including technical feasibility and strategic plans for user adoption. Additionally, the challenge entries will inform the partnership members’ broader commitment and vision to find new ways to approach this decades-long problem.

Submit your idea today!

About the Author: Dustin Renwick works as part of the innovation team in the EPA Office of Research and Development.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Around the Water Cooler: Can Innovations Solve Our Nutrient Problem?

By Lahne Mattas-Curry

Nitrogen is an integral part of proteins, the building blocks of life. But in excess, like anything else, it can have negative effects. In fact, too many nutrients, including nitrogen, can cause depletion of available oxygen in surface waters, toxic algal blooms, hypoxia and acid rain.

The consequences aren’t pretty. Excess nitrogen threatens our air and water quality as well as disrupts the health of our communities, people and land. In other words, some plants and animals can’t live in this kind of environment. I’ve written about this problem before. For example, check out this post on seagrasses.

Nutrient pollution is a problem that affects many areas in the United States, including the Gulf of Mexico, the Chesapeake Bay, and New England’s Narragansett Bay.

To help combat this overwhelming nutrient problem Cleantech Innovations New England  is providing awards to applicant teams of up to $130,000 as part of the i6 Green Challenge, funded by EPA in partnership with the U.S. Department of Commerce and the Department of Energy.

The funds will be awarded to develop ground-breaking and affordable technologies that can reduce nitrogen discharge from septic systems by 95%. (A high proportion of New England communities and more than 20% of U.S. Residents rely on septic systems). In addition, these new technologies should be able to recover nutrients (nitrogen (N), phosphorus (P) and preferably potassium (K)) from the wastewater and/or also create energy.

The technologies must be scalable and affordable, with retrofits to existing septic systems costing in the range of $5,000 to $10,000, and no more than $25,000 for new installations. Of course, on-site nutrient monitoring should also be considered in order to monitor performance.

For more information and to apply for the award, please visit Cleantech Innovations New England. The deadline to apply is January 18th, 2013.

About the Author: Lahne Mattas-Curry works with EPA’s Safe and Sustainable Water Resources research team and is a frequent “Around the Water Cooler” contributor.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Scientists at Work: Paul Mayer, Ph.D.

Dr Paul MayerEPA ecologist Paul Mayer, Ph.D. works in EPA’s Groundwater and Ecosystem Restoration division where he studies riparian zones (the area along rivers and streams where the habitats are influenced by both the land and water) and stream restoration. Dr. Mayer has also worked as a biologist for the U.S. Fish and Wildlife Service.

How does your science matter?

My research examines ecosystem restoration projects—looking at how such efforts also restore various kinds of “ecosystem functions,” such as absorbing nutrients and preventing erosion. More specifically, my colleagues and I have been looking at stream restoration in urban and agricultural ecosystems. Stream restoration uses various approaches to reconstruct or redesign streams that have been heavily impacted by urbanization, agricultural practices, or past land use.

With stream restoration, we’re looking at nutrient uptake (2 pp, 276K), especially nitrogen. Excess nitrogen is one of the ecological stressors that EPA is most interested in because it can cause human health and ecological problems. High levels of nitrate nitrogen in drinking water prevent your body from taking in oxygen efficiently. My work is helping us learn how to “supercharge ecosystems” and enhance their ability to process excess nitrogen.

When did you first know you wanted to pursue science?

I knew I wanted to be a scientist when I was five years-old. My earliest memory is standing in the front yard of my house with my mom and being fascinated by all the birds flying around us. I asked her what kind of birds they were. I knew then, even though I didn’t yet know what a scientist was, that I wanted to know more about the world around me.

Keep reading the interview with Dr. Paul Mayer by clicking here.

Read more Scientists at Work profiles.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Science Wednesday: Nitrogen, Think About It

Each week we write about the science behind environmental protection.Previous Science Wednesdays.

By Sarah Blau

Let’s just take a moment to think about nitrogen. Symbol: N. Atomic number: 7. Atomic mass: 14u. But unless you’re a chemist this doesn’t mean too much…

So let’s think about other aspects of nitrogen. Nitrogen is in the air we breathe, it is in the food we eat, it is a part of the necessary nutrients needed for life. Plants need nitrogen. Animals need nitrogen. We need nitrogen.

But, as is often the case, too much of a good thing is NOT a good thing. Nitrogen exists naturally in the environment, but human energy and food production have led to increased nitrogen levels in the air, land, and water. This excess of nitrogen in our natural resources contributes to many adverse impacts from decreased visibility in the air, to acid rain falling on land, to harmful algal blooms in water bodies, and more.

Nervous yet?

Luckily, EPA researchers take more than a moment of the day to think about nitrogen. They think about sources of nitrogen, the movement of nitrogen in the environment, the chemical changes of nitrogen, and the environmental and public health effects of nitrogen.

EPA scientists and partners in Iowa are testing newly created wetlands as treatment systems for lowering sediment and nitrogen pollution in surface waters draining into the Mississippi River.

In Narragansett, Rhode Island, EPA scientists are investigating how nitrogen from different sources interacts with other pollutants and affects lakes and reservoirs. Results will be used to develop computational tools for more informed nutrient management decisions.

Yet another EPA study focuses on the northern Gulf of Mexico, a.k.a. “The Dead Zone” where excess levels of nitrogen have had severe effects on the coastal ecosystem. Scientists are developing cutting-edge, 3D water flow and water quality models of the northern Gulf in order to inform decision-making about how potential nutrient management and climate change scenarios will affect the Gulf’s Dead Zone and the rivers and streams that feed into it.

EPA’s nitrogen research is ongoing at these and many other locations across the country to answer the overarching question: “How do we protect and sustain ecosystems and protect public health while also providing the material, food, and energy required by society?”

It’s a good question and a hard one to answer. So let’s be glad that EPA scientists know their chemistry.

About the author:  Sarah Blau is a student services contractor working with EPA’s Science Communication Team.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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