In my undergrad classes I had to do several personal carbon footprint calculations (found on the web by organizations such as the Nature Conservancy or the EPA). The footprint models were generally eye-opening in showing how much energy I consumed through daily practices, yet questions were often broad and inexact. Despite this critique I find the calculators a useful tool in allowing an individual or family to look at their activities and find where they can cut down on their greenhouse gas emissions. For these reasons I was excited to find a nitrogen calculator from the Chesapeake Bay Foundation that provided an estimate, in pounds, of how much my family and I contribute to nitrogen emissions in the Bay watershed.
CBF estimates that the average household should have a nitrogen footprint of, at most, 9.1 pounds. My household estimate was double that amount, and maybe even higher than the 20.1 pounds estimated due to values that were underrepresented in the calculator. Our property has a conventional sewer system which contributed a lot to our nitrogen output. Maybe we could look at ways to improve our system, or install other best management practices (rain gardens, rain barrels, etc) to reduce our nitrogen footprint.
Nitrogen pollution is a major issue in the Chesapeake Bay. In my opinion, not much attention is given to household contribution to this issue. I think the calculator is a good tool in raising awareness and allowing individuals and families a jumping off point for ideas on how to reduce their footprint.
The calculator can be found at the following link: http://www.cbf.org/news-media/multimedia/nitrogen-calculator