Random sewage-type "organic" smell on the southwest side of town?

I recently moved to La Cienega and I'm trying to identify the source of a seemingly random sewage-ish smell. It tends to blow in a few times a week, usually around dawn or dusk. My first thought was maybe the septic tank on our property, but our tank is essentially brand new, so it shouldn't be in need of service just yet. Also, there are days where I feel like I can smell it as soon as I get to the 599/Los Pinos area, so it doesn't seem to be localized to my house specifically.

Am I going crazy?? Or is there something nearby that might be producing this smell? It's not a big deal either way, I'm just curious if anyone knows what might be going on.