Clickbait headline. Lots of chemicals are in rocket fuel, and it doesn’t automatically make that chemical dangerous.
The article calls the chemical perchlorate, which is actually a class of chemical, not a single compound. Potassium Perchlorate is used as a thyroid medication…
The article also says this:
Most drinking water contamination comes from the manufacture, disposal and research of propellants, explosives and pyrotechnics, along with accidental releases from factories and rocket launch failures, according to the National Institutes of Health’s Agency for Toxic Substances and Disease Registry.
Which is actually bullshit, perchlorates are not the leading cause of drinking water contamination. I suspect the person who wrote this means “most [perchlorate] contamination”, but I’m not finding any evidence that this is true either; just that pyrotechnics and rockets are responsible for releasing perchlorates into the environment, and that raises perchlorate levels in key areas like west Texas, New Mexico, and northern Chile.