Odor control for plastic urinal installatoon

Venting the waste tank to the outdoors would, I suspect, help a lot with controlling the odor indoors--especially if you use a trap or other seal setup like commercial waterless urinals. (Often, they have a trap that is sealed by some non-water liquid that is less dense than urine, so that it floats on top of the urine in the trap. There are various designs, though, including some that operate on different principles.)