people who say they've gone "18 years" or any other long period of time
without pumping are just asking for trouble. 3 to 5 year between pumpings
should be considered a maximum. That way you never have to worry about
the sludge getting up to the outlet. I'm no expert, but I've been on a
septic system all my life (48 years) and have seen the ups and downs of
them.

--
Steve Barker


I built my house and septic about 18 years ago. I opened the tank last year
concerned about sludge buildup and found only a minor amount in the bottom.
There are two adults and laundry is done off site. Both adults work. Usage
is light. I expect the next 18 years to be the same.