Region
United States
38
California
28
Florida
28
Kansas
13
North Carolina
12
Arizona
11
Illinois
11
Massachusetts
10
Nevada
10
Texas
10
Washington (State)
10
Colorado
9
Maryland
9
New Mexico
8
Utah
8
Floridan Aquifer
7
Idaho
6
Indiana
6
New York (State)
6
Oregon
6
Owens Valley
6
Potomac River
6
South Carolina
6
Virginia
6
Georgia
5
Potomac River Estuary
5
Potomac River Watershed
5
Sheffield Region
5
Alaska
4
Apalachicola River Watershed
4
Cape Cod
4
Iowa
4
Minnesota
4
Missouri
4
Nebraska
4
North Dakota
4
Ohio
4
Pennsylvania
4
Wyoming
4
Cape Cod Region
3
Central Oklahoma Aquifer
3
Colorado River Watershed (Colo.-Mexico)
3
Dakota Aquifer
3
Great Plains
3
Michigan
3
Middle West
3
Montana
3
Oklahoma
3
Puerto Rico
3
San Joaquin Valley
3
more ...