Growing up by Lake Pontchartrain in the 1970s, Kristi Trail remembers the good and the bad of the city’s iconic estuary – days out on the water with her family, but also the polluted conditions.

“The lake was visibly dirty,” Trail said on a recent afternoon at the lighthouse of the Pontchartrain Conservancy, where she serves as executive director, remembering when hazard notices cropped up in the area in the 1970s. “There were dead fish. There was floating trash.”