How certain can you be of the potability of your drinking water? Even if you live in a country that is known for having clean tap water, can you really be sure that absolutely nothing can contaminate it as it travels from the reservoirs to your faucets? Water typically goes through channels of varying materials and may be sullied even at the point of exit if you have dirty faucet spouts. For this reason, it’s important to get hold of water quality testing kits to regularly evaluate the wholesomeness of your drinking water.

Studies show that biological agents persist on drinking water infrastructure, such as pipes, so decontamination is normally necessary to ensure the safety of your drinking water. Water suppliers usually have the decontamination measures in place, but homes and businesses, especially the latter, still need to do their due diligence to make sure that the water they use is clean and safe for drinking. 

Different decontamination options have been explored for different biological agents, but there’s still a lot of room for further work as data gaps still remain. For instance, data on bacterial spore persistence on iron and cement-mortar lined iron – two of the most common water infrastructure materials – show that spores can persist even weeks after contamination. In this case, free chlorine shows limited effectiveness as disinfectant while germinant and chlorine dioxide show more promise. It would be helpful to have material as well on how spores behave with other materials and what other disinfectants can possibly be used to remedy the situation.

When it comes to vegetative bacteria like coliforms, Salmonella, and Legionella, disinfection efforts show better results than those with spores, but data are gathered from studies made on other water systems and are only marginally associated with drinking water systems. The government, as you know, is particularly keen on testing for Legionella, especially in places like hotels, hospitals, convalescent homes, nursing homes, etc. These places often send in for water quality testing kits to make sure that their guests, patients, and residents are not exposed to the potentially fatal bacteria. Meanwhile, real world studies on accidental contamination with E. Coli and Salmonella conclude that flushing and chlorination are usually enough to return the water system to use.

There is clearly more room for further study of drinking water infrastructure in relation to the persistence of biological agents and the appropriate measures for decontamination when these are found present. Recommended research involves covering other common water infrastructure materials besides iron and cement mortar, as well as exploring the efficacy of alternative drinking water disinfectants.

+Duncan Hollis