Scientific American reports that when the US Clean Water Act becamelaw in 1972, the nation's waterways and coastlines were in crisis.
"Oily debris in the Cuyahoga River in Cleveland, Ohio, had notoriously caught fire several times. The southernmost of North America's Great Lakes, Lake Erie, had been pronounced dead or dying. Fish in Californian coastal waters were so laced with the pesticide DDT that it disrupted the reproductive systems of brown pelicans, threatening them with extinction".
Forty years and billions of dollars later, rivers no longer burn, Lake Erie is much healthier and pelicans are off the endangered species list, but much remains to be done. Follow the link to find out more.