The nine states in the northeast region.

The nine states that are in the Northeast Region of the U.S. are:

1. Maine

2. New York

3. New Jersey

4. Vermont

5. Massachusetts

6. Rhode Island

7. Connecticut

8. New Hampshire

9. Pennsylvania

Explanation:

If you look at a regional map of the U.S. then you will see that the nine states that I have listed are in the Northeast region of the map.

answer ( groundwater);