Through a combination of two of my hobbies, I learned that pyrethroids are toxic to aquatic animals. Glad to see that they used "locations [that] were situated away from waterbodies".
Pyrethroids are very powerful tools for insect control (and non-toxic to humans) but any place where you have runoff or ground seepage is going to be a problem.
Aren't those places the ones most likely for ticks to thrive -- areas near bodies of water where animals like deer come to drink?
So hot take: this would only be useful in places where there are not a lot of ticks?
(PS: Permethrin-sprayed clothing is very effective.)