On Mon, 30 Jan 2017 08:09:15 -0500, in alt.home.repair burfordTjustice
wrote:

How so?

A properly maintained Septic system may never need pumped.

20+ years of no pumping is no uncommon.

I asked a few neighbors today, where there are two types it seems (I asked
in email so I had a good sample of a handful of replies).

Some do it every three years.
Others never do it.

I'm not sure what the difference is since they all must be built to the
same code.