I have seen them down the N.J. shore area.But in large parking lot applications.Filled with rocks,they start filtering out contaminants from cars and trucks....preventing oil and gas from mixing with rain water I guess?
Private corporations here have them in parking areas. Maybe it's mandated.
I've seen bioswales under construction. They dig very deep, connect to the storm drainage system, fill with many feet of smooth river rock, top with soil, and plant rather unattractive vegetation.

