Help Finding a Story about Telepathic Kids

Question

The book involves something about polluted river water that seems to actually be contributing to some people's ability to read minds. Sound familiar to anyone?

Answer 1

Might this be Others See Us (1993) by William Sleator...?

When an accidental dunking in toxic waste gives sixteen-year-old Jared the ability to read minds, he discovers horrifying secrets about family members at the summer reunion.

According to this review, a teenage boy, Jared, and a couple of other characters develop telepathic powers as a result of coming into contact with a swamp polluted by toxic waste:

The tension never quite pulls tight in this confusing chiller, perhaps because Sleator introduces too many contrivances. Just before a gathering of relatives, Jared, 16, falls into a swamp polluted with toxic waste; soon after, he discovers that he can read minds, learning—to his horror—that outwardly perfect cousin Annelise is a monster who's already responsible for the death of one fancied rival and the attempted suicide of another. Grandma, who has also fallen into the swamp, enlists Jared and another cousin in a byzantine plot to unmask Annelise by covering her in swamp muck and then distributing copies of her conveniently incriminating private journal. Problems with chronology and unlikely incidents—e.g., Jared drinking swamp water without realizing what it is—make for reader incredulity; the dialogue sounds artificial; and Annelise is a mere caricature of a villain, predictable and two-dimensional. A weak story from an author who's done much better.