John Laing Leal was a doctor who lived from 1858 to 1914 and is largely responsible for having given the whole world an easy way to treat water. His technique to disinfect water using chlorine helped give the whole world an easy way to provide clean and drinkable water. This led to a much lower rate of disease and allowed populations to thrive.
In fact, Leal is credited with setting up the first disinfection center of a U.S water supply using chlorine and even did it secretly for a time. Before it was eventually approved by the courts and became common practice across the globe.
After obtaining a medical degree, Leal opened a medical practice in New Jersey before setting his sights on solving the world’s problem with access to clean drinkable water. This was also because he worked in the local government as a health inspector and saw first hand the problems that dirty water could cause. Leal located numerous diseases and epidemics that happened due to dirty water being drank in homes all across the U.S. which saw him become the city’s chief sanitary advisor for the East Jersey Water Company.
As a physician, Leal knew that chlorine killed bacteria which is why he decided it would be the perfect solution to treat water. He constructed a chlorination plant by hiring George W. Fuller who was a respected sanitary engineer at the time and started to use it to treat Jersey City’s water supplies.
This led to the device being put before the justice system in 1908, where Leal defended his actions and the trial confirmed that the chloride of lime system was indeed cleaning the water correctly & adequately. Leal’s application of this type of disinfection system and its defense in the court of law, made sure that chloride systems were set up all across America to disinfect cities’ water supplies.