The symbolic turning point was when the evening news displayed the Cuyahoga River in fire in central Cleveland.
https://www.smithsonianmag.com/hist...ozen-times-no-one-cared-until-1969-180972444/
This was not the only example of direct threat from polution. In that era certain roads near my rural home town used to catch fire in the summer. The trucks hauling peat moss from the bog to the bagging plant were not covered and the dry Peat that blew off the top collect at the edge of the road. there it was saturated with automobile oil, from leaking engines and transmissions. Every parking place in those days had a large oil stain as gaskets failed in only 10k or 15k miles. Some dry fertilizer mixed in as well. The bagging plant sat adjacent to the railroad tracks & once or twice a similar thing occurred there as dry peat fragments drifted from the bagging area to the brush along the track, which were already littered with residues from the passing trains. Like a lot of plant fibre peat generates heat as it decomposes and catches fire. On hot July days the road would become linked with burning grass & industrial residues generating a nasty smoke.
The Cuyahoga fire story kind of rammed home the fact that we were ankle deep in out own s...t & it was not going away on its own.
Question: Where did household garbage go in the pre landfill era? When I built a house in 1996 on a in town lot we were reminded where. Excavating the foundation, landscaping, and trenching for utility lines turned up several dozen pockets of trash. Broken glass, rusted metal, rotted wood, and unidentifiable stuff. The unidentifiable included lead paint flaked off the metal & rotted wood, or near empty paint cans, used hydraulic fluid, near empty packages of herbicide or insecticide, used containers of rodent poison... Then there were 'dumps' scattered about the landscape. A large open drainage ditch ran through the center of town & the bottom was lined with debris like I described. At the head of this ditch outside town a farmer had a largish 'dump' of a quarter acre. filling the low spot with whatever. The thing leached bits of everything & all its toxins into the ditch, where it flowed off to a small stream & then into the Wabash River. Many of the cities along the Wabash drew their drinking water directly from the river, into which thousands of these minor dumps leaked their collective effluvia.