Region
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Rhode Island
6
Snake River Plain
6
Afghanistan
5
Brazil
5
Camp Lejeune
5
Champlain, Lake
5
Colombia
5
Ganges River (India and Bangladesh)
5
Hudson River Estuary (N.Y. and N.J.)
5
Los Angeles County Flood Control District (Calif.)
5
Love Canal Chemical Waste Landfill (Niagara Falls, N.Y.)
5
Marshall Islands
5
Middle West
5
Northern Hemisphere
5
Northwest, Pacific
5
Pakistan
5
Potomac River
5
Prince William Sound Region
5
San Francisco Bay
5
San Joaquin Valley
5
San Pedro Bay (Bay)
5
Southeast Asia
5
Southern States
5
Suffolk County
5
Susquehanna River
5
Tennessee River Watershed
5
Animas River (Colo. and N.M.)
4
Columbia River
4
Delaware
4
Denver Region
4
Dover Region
4
East (U.S.)
4
Garfield County
4
Gold King Mine (San Juan County)
4
Iraq
4
Israel
4
Italy
4
Jackson
4
Latin America
4
Long Island
4
Mediterranean Sea
4
Middle Atlantic States
4
Mississippi River Watershed
4
Nassau County
4
Oklahoma
4
Pavillion
4
Polar regions
4
Potomac River Watershed
4
Rocky Mountains
4
San Antonio
4
more ...