Road salt on the city’s bridges raised the river’s chlorine levels, making the water more corrosive. This has continued into the present and may have been one reason poorly-treated Flint River water was so damaging to metal pipes.
I shared this because my city doesn’t use rock salt during winter, and its pretty inconvenient as a driver. So I was surprised to learn why.
It’s disingenuous to say it’s the PRIMARY contributor, but it is a factor!
Good thing you read more of it than I did. I just searched the document for the word “salt”!
I was surprised to hear the claim too. I thought I had read years ago that it was metal fatigue at the welds. Akin to a paper clip being bent to many times some of the welds fatigued to failure due to years of flexing.