Stacking septic leach fields
I'll echo the other comments, in a slightly modified manner. The idea of 100 feet continuous is not necessarily a valid interpretation. 4 x 25 still provides 100 feet. Accordingly, stacking can refer to horizontal placement, rather than one atop the other. This was confirmed by my contractor upon a recent field replacement. Depending on your local codes, the 100 feet doesn't have to be monolithic. If the lot requires it, a pair of 25 footers side-by-side linked to another location containing another pair would still qualify.