The discovery of chlorine was first made in 1774 by a chemist named Karl Scheele. From that day forward, science was looking for ways to make use of these qualities of chlorine. By the 1800s, chemists had a much better understanding of chlorine’s properties, and in 1850, for the first time, chlorine was used by a doctor in London, England – John Snow, to attempt to treat the devastating outbreak of cholera in London’s poorest district.
He had successfully traced the origin of the outbreak to a community well in a public square and poured chlorine into the well to try to stop the spread of the disease. His use of chlorine in this way led others to try to reproduce the results, and in 1897, “bleach solution” was used to sterilize potable water mains in England following a typhoid outbreak, quelling its spread.
With firm evidence of chlorine’s usefulness in preventing water-borne illness, in 1908, New Jersey became the first district to begin using continuous chlorination. The unprecedented level of safety in public drinking water supplies that followed has been hailed as the greatest major public health achievement of the 20th century. It virtually eliminated potentially epidemic outbreaks of diseases in major populations and has saved countless millions of lives.
They didn’t know it then, but chlorine can come with a cost. The creation of disinfection by-products is a reality and can pose a significant danger to people and to the environment as they are produced.
Chlorine and other chemicals used in water treatment have the potential to create hundreds of different disinfection by-products. Some are harmless, and some can be extremely harmful. Of all of these chemicals, the two most harmful groups would be trihalomethanes (THMs) and haloacetic acids. The names sound long and intimidating, but what are they?
Chlorine and many of the other chemicals used in water disinfection (peroxide, ozone, etc), are known as oxidizing agents. We will use chlorine as a standard example of what an “oxidizing agent” is.
Chlorine molecules are added to the water, and they begin attacking microbes and stripping the cells of their cell walls, effectively destroying them. Even in today’s modern world, this process is not especially well understood by science. The end result, however, is the destruction of the pathogen. Despite the lack of knowledge about the actual process, it’s well established that this process does work to disinfect water.
During the oxidation process, some of the chlorine is destroyed, but the chlorine that remains (called “residual”), can bond with other types of organic substance in the water. When this happens, it creates chemical products that are neither intentional, nor avoidable. Any organic matter in the water, such as decaying leaves, animal corpses, vegetation, or fecal matter can mingle with residual chlorine and create disinfection by-products.
Trihalomethanes and other disinfection by-products can be deadly.
Water Superstore has numerous ways to remove chlorine from the water in your whole home.