Typical drainfields are 4 inch diameter slotted pipe bedded in 3/4 inch washed gravel with a foot of soil cover. Sometimes during landscaping the surface cover is partially removed exposing the slotted pipe. This is usually an easy repair. Older (like 25+ years) drainfields may clog with suspended solids that have built up over time. That repair is replacement of the field. Having the septic tank pumped and using additives like Ridex on a regular basis is wise.
If there is "horizontal runoff "than it is in violation of code and the entire septic system would have to be reworked and inspected.
Constance Drury GRI,CRS
Keller Williams Mountain Partners
28739
