The concrete tanks can have problems too. Mine had a baffle fall over on the gray water side. When it fell, it broke off the elbow on the discharge line. Without the elbow any floating solids can go directly into the drain field. I imagine an earthquake is what knocked the baffle over. That was a fun smellyy job to replace.
I also have rerouted my gray water from my septic. Wash machine and the 2 bath tubs gray water is now used to water my lawns. The lawn loves it. So now the only thing entering the septic tank is toilet and kitchen sink water.
I also have rerouted my gray water from my septic. Wash machine and the 2 bath tubs gray water is now used to water my lawns. The lawn loves it. So now the only thing entering the septic tank is toilet and kitchen sink water.