I hate to bring this up again since the last time we discussed this on this forum about a year ago or better, but I have been doing more local research. When talking to freinds or neighbors or helping friends with tractor work, I've asked about their septic systems.
I will still have to hold to the fact that pumping septic systems may only be required in areas where, for one reason or another, the soil doesn't do what it is supposed to.
In talking with people in my area.. here are some stats:
2 septic systems that I know of older than 50 years. Never been pumped, still working great.
5 older than 40 years that I know of that has never been pumped and still working great (one of those did have to have the tank replaced due to a concrete truck crushing it.)
My own house as well as my 2 neigbors (all built at the same time), 20 years and still going strong.
Many others including my co-workers ranging from 10-20 years with no problems and no pumpings.
Believe it or not, out of the 20-25 people that I have asked, I'm batting 100%. Not a SINGLE ONE in my area has ever had septic problems, and none of them have ever had their system pumped.
I've just got to say from personal experience. Pumping is just NOT necessary in all areas of the country.