I have been allowing my two horses to graze in a pasture that includes our leach field. The ground around the leach field is sandy & dry. We mow the leach field with a Kubota small tractor to help keep it dry. One of my neighbors told me that the tractor and the horses will ruin the leach field. We just bought the home in May, and the previous owners had horses that they allowed to graze, and they said they never had septic problems. Are we substantially increasing the risk of septic failure by our brazen activities?
Compaction is a problem in drain fields. The surface can become so compacted that oxygen will not pass throught the dirt to get to the effluent to treat it in the drain tiles. It may take a long time to develop a problem. It is not “if”, it is “when”. I would not allow the horses to run over the drain field if it was mine.