Your Morning Coffee and Bacteria in the Water

What does caffeine consumption have to do with water quality? Well according to researchers in Canada, your morning coffee could provide a red flag to alert officials of a sewage overflow and likely bacteria contamination in local waterways.

About 3 percent of the caffeine consumed in coffee, tea, chocolate and other foods and beverages ends up in the sewer system. Scientists at the University of Montreal found a direct correlation between levels of the chemical in rivers and other water bodies near urban areas and contamination by fecal coliform bacteria.

Environmental chemist Sébastien Sauvé and colleagues were looking for alternative makers for coliform contamination, because the bacteria isn't always that easy to detect. The scientists considered medications, especially the anti-seizure drug carbamazepine because it breaks down slowly in the environment, but caffeine proved to be the winner. "[I]t's probably very difficult to find one home or two homes where there isn't one person taking coffee, tea, Coke, chocolate, or some medication that contains caffeine or energy drinks," Sauvé told LiveScience.

Across the United States and Canada, urban sewer and stormwater systems are aging and in need of repair. Monitoring for caffeine in the waterways could alert cities to breaks in sewer lines and prevent outbreaks of illness caused by sewage contaminated water.

In cities like Montreal or Syracuse, NY, which we highlighted in our post on green infrastructure, combined sewer and stormwater systems routinely overflow into rivers and streams during periods of heavy rainfall.

Fecal coliform is itself an indicator bacteria of bigger contamination problems. While the most abundant bacteria in sewage, it rarely causes disease. However, contaminated water supplies can transmit E. coli, cholera, typhoid fever, shigellosi, salmonellosis, and gastroenteritis, which is caused by several different pathogens.

This kind of contamination is a municipal treatment and water-quality issue, not something addressed by point-of-use filtration; it's still possible to come in contact with pathogens from sewage by swimming in contaminated water bodies. Caffeine could improve early detection methods for health officials to close beaches and alert the public to potential risks.