Cistern Pipes Photo Credit: VI CONSORTIUM
Using cistern water without properly treating it may increase your chance of getting sick from a water-related illness, according to a new evaluation from the V.I. Department of Health in collaboration with the Centers for Disease Control and Prevention (CDC), and Love City Strong.
During the summer of 2019, health officials tested the cistern water quality of 400 randomly selected households on St. Croix, St. Thomas, and St. John, D.O.H. said. The field team tested for the presence of bacteria called Escherichia coli, an indicator of human or animal feces contamination. They also tested water from a sample of 47 households for other types of germs and indicators of human sewage/septic contamination.
Results show that water in 4 of every 5 cisterns tested positive for E. coli contamination. Tap water sourced from cisterns and drawn from kitchen taps showed E. coli contamination in 58 percent of samples, the Dept. of Health said.
Additional cistern water testing for the subset of 47 households found:
- 36% tested positive for Cryptosporidium (17 households)
- 32% tested positive for Salmonella (15 households)
- 30% tested positive for Naegleria (14 households)
- 9% tested positive for human sewage/septic contamination (4 households)
- 6% tested positive for Leptospira (3 households)
- 0% tested positive for Giardia
Protect yourself and your family from getting sick
Using cistern water without properly treating it increases your risk of getting sick. There is some risk of sickness if you use untreated cistern water for any of the following tasks: drinking, washing fruits or vegetables, brushing teeth, rinsing your sinuses, washing an open wound, or bathing or showering, the health department said. D.O.H. recommended that households do not use untreated cistern water for the above tasks.
Consider treating your cistern water to remove or kill harmful germs or use bottled water to make sure you have safe water to drink. If you cannot treat your cistern water, you can reduce your chance of illness by boiling water for at least one minute before drinking it or using it for the tasks above. If you use untreated cistern water for any of the tasks listed above, remember there is some risk involved.
The following cistern water treatment options can help keep you and your household safe:
- A household filtration system with ultraviolet light (UV) – A properly installed and maintained system can provide water that is safe to drink and use. (Note: Sediment, refrigerator, faucet-mounted and pitcher (e.g., Brita) filters alone do not remove these germs.)
- A household chlorination system – A properly installed and maintained chlorination system can kill most harmful germs but will not kill parasites such as Cryptosporidium.
For small amounts of water:
- Boil water for 1 minute, OR
- If you cannot boil water, such as during an emergency or power outage, add household bleach (1/8 teaspoon or 8 drops per gallon of water).
The Dept. of health said it is working with the CDC to identify and communicate specific environmental and household management practices to help USVI residents understand and address contamination risks to their cisterns.
