John L. Leal

John Laing Leal was an American physician and water treatment expert who, in 1908, was responsible for conceiving and implementing the first disinfection of a U.S. drinking water supply using chlorine. He was one of the principal expert witnesses at two trials which examined the quality of the water supply in Jersey City, New Jersey, and which evaluated the safety and utility of chlorine for production of "pure and wholesome" drinking water. The second trial verdict approved the use of chlorine to disinfect drinking water which led to an explosion of its use in water supplies across the U.S.

5 May 1858

Born on the same birth day (5 May): Archibald Wavell, 1st Earl Wavell • Blind Willie McTell • Heike Henkel • Hubert Howe Bancroft • John Frederick, Duke of Württemberg • Josh Weinstein • P. J. Tucker • Shawn Drover • Shoko Nakagawa • Simon Rimmer • Thomas Cecil, 1st Earl of Exeter • Tiffany Roberts • Yossi Benayoun

Born in the same month (May 1858): Belmiro de Almeida • Carl Richard Nyberg • Graham Wallas • Heinrich Berté • J. Meade Falkner • Édouard Goursat