Oi!

In the States there are over 20 million septic tanks, used by over 50 million people.
The fitting, maintenance and cleaning of septic tanks is a very large business.
It is understandable that people wishing to justify their existence and income
will provide mis-information to the general public on whom there fortunes rely.

Evidence seems to show that around 50% of septic tanks and drain fields have
either been installed incorrectly or are not working correctly.

Taking into account that the first septic tank was installed by John Louis Mouras
in Vesoul, France in 1860, there has been plenty of time to get it right.
A well designed installation does not have its inspection covers buried in the ground
why would anyone do that? Except to make life difficult for the owner, who then
cannot inspect its contents. Why are so many drain fields installed at the wrong
angle and why are so many installed without inspection chambers at each end
of their lines, is this just to make life difficult?

It is very simple to manufacture a 10 foot pole with a plastic bottle on the end (small
enough to fit in a 4 inch pipe) to lower down the inlet T and to feel the top of the sludge, used every few months it shows how the tank is filling up, it shows how the anaerobic process relies on heat to process the solids and how the solids level rises in the cold of the winter only to
lower in the hotter summer months. Showing that over a typical year, the level will
often remain constant. You don't have to put your head anywhere the tank opening,
in any event the mixture of gases disperses almost instantly on removing the lid.

The hardening or clogging of a drain field is in part due to unsuitable ground conditions, but is usually down to the amount of common salt/sodium that ends up in the drain field, if the lady of the house takes the trouble to wipe excess salt of the plates and does not use a dishwasher or water softener then the small amount of sodium in our waste has little effect.

And yes, as I wrote earlier, using the septic tank as designed, will result in its longevity, likewise
restricting the amount of cold water that is dumped in a tank, will enable the suspended solids
to settle within the tank, instead of being flushed into the drain field, where they will eventually
hinder the passage of liquid through the dry earth. Arranging things so that there is an eight
hour resting period during every 24 hours, where the suspended solids have a chance to
settle and the drain field to dry out is useful

Dunno if you ever found your tank, but I was talking to a retired contractor friend yesterday, and he said that the building code here in Ontario specified the tank has to be within 3 to 10 feet of the building....

Interesting point, it seems that over the 23 years I have been interested in these things, every year I find more and more strange rules, you would think that there was a best place to put them and a best way to install them but, every country and state and county seems to have their own idea and rules.
And of course places like California and the European Union are constantly updating their rules as we all get more and more worried about pollution and ideas change from being somewhere to just get rid of things to considering how our aquifers, rivers, seas and lakes can be saved from pollution.

There are also numerous regs regarding location relative to streams etc now too, although there is a lot of "Grandfathering" too to get around some of that.