Monday, December 30, 2013

Nitrogen and Phosphorus

It might seem counterintuitive but excess
nutrients are a serious threat to marine
life.  Excess nutrients cases a reduction of
oxygen in water which leads to hypoxia.
Click for photo credit.

At the close of the year, I write a series of posts on overlooked environmental stories.  In previous years, I wrote about the acceptance of the "new normal" in climate change, the growth of GMO food in the US diet, the expansion of benchmarking in sustainability management, the growth in the science of Mars, the acceptance of climate change by big energy, the high carbon cost of the internetwhite nose syndrome, the lack of clear US energy policy, the normalization of sustainability in everyday lives, the decline of the nuclear energy industrythe end of sprawl, and population growth.

It is interesting to go back to those posts and gauge their relevance in today's conversations on the environment and sustainability.  If you have any suggestions as to what I should feature in this year's series on overlooked environmental issues, send a note or leave a comment.

So far this year, I've written about the science of early humans, the stark reality of climate change, the acceptance of junk science by the American public, the return of nature and the growing importance of the Internet in documenting environmental science and policy issues.  You can catch the posts herehereherehere and here.

My final post for this series and for this year is on the growing problems with nutrient pollution.  The U.S. and many other parts of the world have done an amazing job in eliminating public exposure to harmful pollutants like heavy metals, volatile organic compounds, and a variety of other unhealthy chemicals.  However, we still are unable to fully address the vexing problem of nutrient pollution, particularly nitrogen and phosphorus.

The problem with nutrients is that they are often non-point pollutants, meaning that there are multiple sources of the pollutant, often in low concentration.  However, with time, the low use rate adds up and entire ecosystems can change as nutrients slowly increase.

Storm water is an important source of nutrient pollution.
Click for photo credit.
What are the sources of nitrogen and phosphorus?  According to the EPA, there are 5 main sources:  agriculture (from fertilizer and manure runoff), storm water, wastewater from sewage treatment plants, burning of fossil fuels (for nitrogen), and home use (particularly home fertilizer use and septic systems).

The real challenge of managing nutrient pollution is that it is difficult to regulate the sources.  How do you cut fertilizer runoff from a farm?  How do you ban fertilizer use for home lawn or garden use?  How do you reduce sewage or septic system discharges?  How do you reduce stormwater runoff?  Reductions are possible in all of these situations, but extremely difficult and time consuming.  They are also politically and socially difficult.

But the problems are becoming acute.  Some areas of the U.S. have so much nutrient pollution in the groundwater that it is likely that important aquifers will become unavailable in the coming decades.  Algae blooms in coastal waters have caused massive fish kills in important recreational and commercial fisheries areas like Long Island Sound.  Whole ecosystems, like the Florida Everglades, have transitioned from natural low nutrient environments to high nutrient environments, thereby transforming ecosystems into something completely different from what they were.  This drives extinction, exotic species expansion, and a wide variety of other issues.

The problem is also an international one.  As populations grow and modern agricultural techniques and suburbanization expand across the world many areas are experiencing unprecedented nutrient pollution.

Many of us have been working on these issues for a long time.  There have been some successes, but many problems remain in the U.S.  Some things to look for in the coming years:

1.  More fertilizer bans.  I expect we will see more fertilizer bans in communities.  As people start to become more aware of the problem and how it is impacting their water quality and local environment, there will be greater acceptance of fertilizer bans.  The green lawn will be socially out.  They are already very uncool.

2.  Off the septic.  We will see more and more areas moving off septic systems.  It is believed that a significant portion of the nutrient problem in Long Island Sound and many other areas of the U.S. is caused by nutrient pollution from septic systems.  There will be greater effort to get homes off of septic systems and onto sewer lines.

3.  Nutrient recycling.  There are many who have advocated nutrient recycling for years.  Indeed, farmers who use animal wastes for natural fertilizer have been doing this for generations.  However, I expect we will try to find innovative ways to remove nutrients from wastewater, stormwater, and agricultural runoff in the coming decades.  Right now, significant amounts of sewage waste are added to agricultural fields.  There have been concerns with this practice due to the expansion of pharmaceutical and their subsequent release into sewage and then onto fields.  How can we remove just the nutrients?  Algae biofuel has some strong potential.  You can read about this innovative source of energy here and here.

4.  More engineering and regulation.  I expect that we will see more engineering solutions to stormwater management, agricultural runoff, and manure field runoff.  The engineering fixes will cost more than current practices and will have to be built into code, which will require greater regulation.  No one likes expanded regulation of course, but strong local government regulation is one of the only ways to manage non-point pollution.

5.  More problems.  I don't see a clear way out of the nutrient pollution mess we are in at the present time.  We will have some fixes, but there will be some areas that will be very difficult to manage.  Thus, I expect we will continue to see critical problems in some areas such as the Mississippi delta region in the Gulf of Mexico, Long Island Sound, and some groundwater systems.

While there is much cause to be concerned, there are some success stories.  Just take a look at Chesapeake Bay. There, a regional approach to managing the Chesapeake watershed led to reductions in nutrient content of the Bay.  Clear regional environmental management was the key to success in that area.  The Bay has a long way to go, but great improvements have been made since the 1980's.  Poke around this Website and you'll get a sense of how strong multi-government and regional management can solve serious nutrient problems.

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