Take the runoff water from the road with high nitrates and collect it in ditches with algae or Hydrilla absorbing CO2. Convert the algae/aquatic plants into bio

Take the runoff water from the road with high nitrates and collect it in ditches with algae or Hydrilla absorbing CO2. Convert the algae/aquatic plants into bio diesel or dry it and make soil for plant nurseries. Edit: Taken from Wikipedias Hydrilla article, "This abundant source of biomas is a known hyperaccumulator of Mercury, Cadmium, Chromium and Lead, and as such can be used in phytoremediation." http://en.wikipedia.org/wiki/Phytoremediation http://en.wikipedia.org/wiki/Phytoremediation