As with most types of construction work, everybody has their opinion on how to backfill a basement.  I've heard of, seen, and repaired foundations with variations from pushing the existing clay soils back into the hole after the basement is constructed with no crushed rock, no drain tile, no sand or gravel to the extreme opposite of people using over two hundred cubic yards of crushed rock in their basement construction.  Which way is correct?  Certainly not the first scenario; and the second scenario is way too expensive and unneccesary.   My time proven technique with no call backs over the past twenty one years is this: 

Today, I am going to discuss the basics of laying a residential sewer lateral in the ground.  Whether the pipe is to be installed inside of a structure or outside, the basic methods are the same. Typically, you will need a starting elevation and an ending elevation.  To determine your pitch or fall, measure the difference in elevation between start and ending points and divide the number of horizontal feet of run into the number of inches of fall.  This will give you your "drop" per foot of pipe.  It is important to note that when installing sewage pipe, your drop should not exceed 1/4" per foot.  If your drop exceeds this number the water in the sewage tends to flow faster than the solids.  This can result in a plugged sewer line.  A quick example;  if you find that you have 10 inches of drop between start and ending points and you have a 100' run of pipe to install, you would drop .1 inches per foot.  This is a very small drop, particularly for smaller pipe.  The recommended pitch for 4" pipe is 1/8" to 1/4" per foot.  For drops less than or greater than the recommended range there are other solutions.  Contact us for more information.  

This has been a studied and talked about topic within our county over the past few years.  St. Louis County, after the first recent season of septic system freezing problems conducted a study to determine the causes of the freeze ups.  It was found that one of the major reasons a septic system freezes, particularly a newer system, is due to poor construction practices.  Another reason is due to lack of insulation in areas that are shallow and or prone to freezing due to any type of traffic (foot or vehicle).  I have heard people claim that mound systems don't work because they freeze in the winter.  The reality is is that if the entire system is designed and constructed properly, it is very unlikely that there will be any problems at all.