Was inspecting a 60-70 yr old home in Collinsgwood, NJ last week, and saw this metal cover on the ground at the left front side of the house that said Sanitation Vault. It was filled with dirt and did not seem to be in use. What could it be? Part of an old septic system? well system? Drainage?

The homes on this street have been public sewer for decades.

Thanks guys!