It seems normal to me that folks would want clean air and clean water. However some seem to be adamantly against having either/both. Why?

  Today's big trucks burn fuel so clean, they produce cleaner air coming out of the exhaust than going in the air filter. Hard to believe. These trucks require that 'Diesel Exhaust Fluid' be added during combustion to help the process. Perhaps you will notice signs that advertise 'DEF' at truck stops. If you see a truck belching black sooty exhaust, it is just carbon particles that fall to the ground. The EPA makes sure of it.