house septic help!

Well aint that some sh&t!!!!! (Sorry, could not help myself) From what I understand the vaults allow you to downsize the drain field quite a bit, as long as your soil allows them. I will be building a home in a different spot on our property so I will need another septic/drain field. I will be doing it myself and plan on the vaults. Neighbor used them here in Washington. He did the field himself and priced it out both ways. Ended up being less $$ using the vaults then rock, largely because the local gravel yards had no rock at the time.