When the Conowingo Dam opened to fanfare nearly a century ago, the massive wall of concrete and steel began its job of harnessing water power in northern Maryland.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/experts-warn-dead-zone-chesapeake-bay-pollution
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/phys
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-pollution
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/dams
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/hydroelectricity
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/united-states-america-us
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/sewage-pollution