I can only speak for what I know. Septic systems are suppose to perk 'up', not leach down. It can leach down to a water table 150' from the well just as easily.

And states tend to accept 'national' regulations. Like the building code. Hurricane clips are required in Michigan and Illinois. Really? When was the last hurricane? We have tornadoes, and those clips will just make the top plate go with the rest of the roof. Make 'em strap it from roof to foundation if anything. But then again, my shed (nailed properly) has survived the same 30+ years of storms as the house with the national building code requirements.

Sometimes it's just overdone.
Don't even get me started on stuff like 'fire-rated plywood'. I've had to stand face-to-face with Fire Chiefs and tell them I have to use it because of 'national codes' (even though he begged me not to because it risks lives of firemen).

I do not work here, but the benefits are still awesome
Make your sound your own!