The petroleum industry uses deep-well injection to dispose of its hazardous waste.
though the wastes are pumped into porous rock, the industry claims the wells are safe because

because they are situated near aquifers

Explanation:

Aquifers is a underground layer of rock which can hold and release water in desirable amounts so petroleum industries claims the well are safe.

from the original order (top to bottom) the new order will go

1 (founder)

4 (hawk)

2 (mutate)

3 (next generation)