They take all of the design away from us here. The soil scientist tells us what the perk rate is, asks if we're doing bags, domes, or gravel, then tells us how many feet we need and how many lines. unless it's considered an advanced system, then they just tell you exactly what you're building and where.
18 years ago, "Gravel-less" was the Norm, & Sand Filters were Grudgingly accepted.
All Talk about the Mound System was like telling the Health Department "Hi! I'm a Convicted Rapist, & I'm dating Your Daughter!".
Then, "The State Powers" proclaimed "Ugh! Gravel-less Systems Bad!", ... So, "Sand Filters" became the Norm, & Mound Systems were grudgingly accepted.
Now, .... "The State Powers" , have decided "Ugh! Sand Filters Fail!", & the New Norm is the Mound System. SMH
All Leach line Systems that fail a yearly inspection by the local Health Department, are Condemned with the Owner being given an order to upgrade, & that applies to Sand Filters also.
Frankly, ... I Believe that it's just Big Brother, exerting more control in our lives, down to the level of how We Pee & Poop.