In the final stage of our analysis, we tracked carbon, nitrogen, phosphorus, and potassium through each of the scenarios (Figure ). The mixed excreta system has comparably low capture of carbon as biochar (12% [3 -38%]), due to the carbon emissions associated with pit latrines (Figure ). Source separation reduces the loss of carbon in the frontend and captures more carbon as biochar for the source-separated scenario (i.e., 28% [10 -81%] of carbon is captured as biochar; Figure ).