We had a septic tank (70s tech version) when I lived in Mass as a kid. My dad dumped a box of Rid-X in about once a month and we had it pumped out at some interval of years and the guy who pumped it always said it was the best and most well maintained tank he ever saw. We never had issues, that I can recall, in 17 years living there, and beyond the above, did no maintenance as far as I am aware.
I do remember that the snow always melted first over the area the tank was at
Later I rented a house (5 years) in New Hampshire that had a septic system. It was not that well maintained, though I did occasionally put Rid-X in. It had to be pumped out at least once while I rented. I rented 98-2002 (almost 5 years) and the house was from the early 80s. The guy who pumped it out was not impressed with its condition.