In 1998, New York listed Keuka Lake as impaired after DDT contamination. 16 years later, fish-tissue data led officials to remove the lake from the impaired waters list

Keuka Lake DDT cleanup shows how a pesticide banned decades ago kept affecting fish through contaminated soil and runoff. The problem began long before todays conservation efforts. DDT settled into farmland and could travel with eroding soil toward the lake. New York farmers later adopted erosion controls, cover crops and better pesticide practices. Fish testing eventually showed much lower DDT levels. That helped restore safer fish consumption at Keuka Lake.

Raccontata daeconomictimes.indiatimes.com