Groundwater Contamination and Cow Poo: A Major Contributor to Global Warming

This is a project I've been working on for a while now, mostly because time has not permitted me to finish it and I've had other "issues" to deal with. I've been doing lots of research about global warming, water contamination and whether or not the two are related.

While watching a documentary, they mentioned how methane from cows (i.e., cow farts) are a major contributor to the greenhouse gasses and how cow manure is a major source of nitrate released into groundwater used for drinking. Fortunately, there is tons of data available, the primary source being the Environmental Protection Agency (EPA).

I wanted to understand the geographical distribution of three factors:

1. The percentage of each State with high groundwater nitrate concentrations.
2. The total area (square miles) of each State with high groundwater nitrate concentrations.
3. Where the cow crap comes from that pollutes groundwater used for drinking.