THE BLOG
08/23/2013 11:05 am ET | Updated Oct 23, 2013

The Nitrogen Cascade: The Next Big Pollution Problem

I know that your head is still whirling around thinking about climate change and what to do about it. The earth has hit the 400 parts per million level of carbon dioxide for the first time in 2 million years. The preponderance of drought, shrinking glaciers and super storms, plus actual bona fide peer-reviewed scientific evidence, erases any doubt to any rational educated person about the reality of climate change. I hate to break it to you, but we have another upcoming pollution problem that is just as bad -- The Nitrogen Cascade.

There have been mass animal deaths of manatees, dolphins and pelicans in the Indian River Lagoon in Florida reported this summer in The Huffington Post and The New York Times. The probable cause -- the Nitrogen Cascade. Recent surveys by the Harbor Branch Oceanographic Institute at Florida Atlantic University concluded these estuary waters contained 45 percent more nitrogen than is acceptable. A lot of nitrogen pollution comes from septic tanks, storm water and agricultural runoff. But much of it comes from the air too.

Seventy-eight percent of the earth's atmosphere is essentially inert nitrogen gas. Since life first appeared on earth, nitrogen has gone through a biological cycle from 'inert' atmospheric to 'reactive' organic nitrogen and back to inert nitrogen. Every bit of protein from every animal and plant also has 'reactive' nitrogen in it at around 6 percent the dry weight of protein. Nitrogen is taken up by nitrogen fixing plants like alfalfa, soy beans and legumes and made into proteins. The plants are eaten by humans, insects, microorganisms and animals or they eventually die and decompose, recycling their reactive nitrogen. In each case, the nitrogen is returned to the cycle when these organisms die or excrete. Thus was the balanced life cycle of nitrogen.

Then in 1880, Haber invented a chemical process that took natural gas (methane), stripped the hydrogen from it and combined it with atmospheric nitrogen to make ammonia. Ammonia was then used to make gunpowder and other munitions. After WWII the ammonia was used to make fertilizer. The Green Revolution was launched with the idea that, since fossil fuel is so cheap, one calorie of food energy can be created using one calorie of fossil fuel energy.

So now ammonia is a fertilizer and the base chemical of the fertilizer and munitions industry. Only a small portion of the nitrogen in ammonia-based fertilizers actually makes its way into the foods we and livestock eat. The rest is emitted to the air or becomes runoff. The food ends up as human waste and livestock excrement. While the majority of the human waste ends up in wastewater treatment plants, the livestock excrement does not. The majority of this reactive nitrogen ends up as runoff and ammonia emissions. The runoff 'fertilizes' standing bodies of water causing blooms of algal growth which robs the oxygen from these bodies of water causing death of aquatic organisms.

Atmospheric, 'inert' nitrogen, is also converted to reactive nitrogen in a variety of industrial human activities producing airborne particulate matter (PM), NOx and nitrous oxide, representing about 5 percent of the impact of greenhouse warming gas.

There is so much nitrogen now that it is cascading into and overloading the ecosystem.

Collectively agricultural runoff now represents the #1 water pollution problem in the United States according to the EPA. It is why over 50 percent of our rivers and streams are polluted, why the Chesapeake Bay is almost dead, why there is a large and growing dead zone in the Gulf of Mexico and why there was a massive die-off of dolphins and manatees in Florida

Bobby Kennedy Jr., working with NRDC, Riverkeeper, and Earth Justice, has been victorious in court and the law now identifies concentrated animal feeding operations (CAFOs) as being obligated to comply with the Clean Water Act as would any other point source water pollution releaser. But the laws are only slowly being enforced. Especially because the agricultural economy is in the crapper right now and most solutions only add to the cost of livestock maintenance.

Lancaster, Pa., is one of the worst places in the country for nutrient pollution due to livestock releases and emissions. Running through Lancaster, the Susquehanna River transports 145 million pounds of polluting nitrogen into the Chesapeake Bay each year. There, Peter Hughes, a farming consulting engineer, innovated a system of trading nutrient credits. It is built around the philosophy of using market forces to incentivize farmers and others that if they could mitigate nitrogen releases cheaper than a wastewater treatment plant, they could sell those credits to the treatment plant to help it meets in compliance targets. The farmers would then use that money to pay for the nitrogen mitigating technology. More pollution would be mitigated for less money, serving planet and pocketbook.

I was fortunate to work on micro-aerobic respiration, one of the most effective and cost-effective nitrogen pollution mitigation technologies, developed by Dr. Jerry Northrop. Now installed on giant Kreider Dairy in Pennsylvania, it is a process that uses bacteria to convert the polluting nitrogen in animal waste back into inert atmospheric nitrogen. The nitrogen credits produced by this technology are being bought by the water treatment utilities as a more cost-effective way to comply with their discharge permits.

After agricultural runoff, the next big nitrogen challenge is storm water releases. The total nitrogen in them is equal to the total nitrogen in wastewater releases, but almost all municipalities merely pay the fines as the less expensive way of dealing with mitigating this form of nitrogen pollution. Otherwise it would require a capital investment equal to their existing waste water treatment plants just to handle the storm water for the few rainy days per year.

Now that nitrogen pollution mitigation technology has proven to be cost-effective enough that it increases farmers' profits, governments can start enforcing the laws on the books or leave it to the environmental organizations to file lawsuits. The environmentalists have had a very good record of success in this space. And then maybe we can actually reverse the Nitrogen Cascade.

CORRECTION: An earlier version of this post indicated that the Susquehanna River transports 40 percent of polluting nitrogen into the Chesapeake Bay each year. It transports 145 million pounds of polluting nitrogen.