Eigenvector wrote:
A couple of questions here.

1) How long does a leach field last in an average septic system? Does it
have to be replaced every so often even if it was used properly, or is
improper use the only reason the leach field goes bad?

2) In an older septic system, how much impact force can the leach field
take before damaging it? I have to fell a totally rotten tree and it will
unfortunately land right on the field. I can of course minimize the blow by
chunking the tree up rather than just chainsawing it down in one big cut.
Even still do I have to treat the leach field delicately or can it tolerate
moderate blows?

a lot depends on the type of soil. if you have good well drained sand,
it will last longer than if your soil is marginally permeable. it is
critical to get your tank pumped regularily--every three to five years.
otherwise, solids can be flushed into your drainfield and will plug up
the system.

how much impact a drainfield can take depends on what kind of system it
is and how deep the drain tile or whatever are buried. if your pipes
are several feet below the surface, i think they could take quite an
impact. but i suppose you could get unlucky and spear a branch into
the ground. but you could dig up a pipe and repair it i suppose.