It is so disgusting to enter a lav and see the holding tank fluid in the toilet sloshing around near the brim. Who has the courage to "operate the device"? Who has the final check on those fluid levels? Who can bear the smell in the F cabin? This seems to be a problem on DL MD-88s ex-PHL for ATL. I've never seen this problem from other airports.
Makes me wish I didn't have a "sensitive nose"... but even then, I wouldn't "operate the device" without a hazmat suit on.