Someone pointed me to the 0.7.6 patch notes for this on the Discord: “Compost Yards now automatically dispose of excess waste, allowing them to continue to collect waste even if all 3 compost storage areas are full.”
I am not seeing that behavior currently. I have a relatively stable city, ~1200, and ran into the situation that waste started building up, causing rats, and then bubonic plague as all of my compost yards were full. I wound up having to add several more to get it to calm down. If they were still collecting, it was not at the same previous rate.
I can confirm that this is a problem with the current version 0.9.2c although it was already present in 0.9.1
Once the compost yard is full, no further human waste is collected.
Mildly disappointed that Zantai appears to be in denial of this bug by suggesting insufficient yards.
Building extra yards they full up too and once full also stop collection.
The only effective work around send to be to have many tiny fields so that the compost can be wasted as quickly as possible to keep the yards empty.
Zip up the entire TownName_###### folder along with the .map file and .sav that reproduces the issue. If the files are too big, you can use a service such as Google Drive to share it with us.