Yellow gold

I read this article yesterday on Gizmodo and it started me thinking. Before industrial production of chemicals, urine was widely used to take advantage of the naturally occuring ammonia contained within it. Fulling - Wikipedia Today, it seems, we may be on the brink of finding returning to using our waste as a valuable resource. However, as the Gizmodo article state, it’s difficult to source human urine because of our sewage systems. I’m curious if anyone has a design answer?

I was thinking of a seperate storage tank, like a septic tank, but for urine. I have no clue what problems that might have. Any ideas?