If you are installing a cold-water storage tank to hold drinking water, you may have your own private water supply, particularly if you live in a rural area. The water storage tank could be a rainwater tank connected to your roof, or a tank connected to a nearby stream, bore or reticulated water supply. More information can be found in the Water Tank Information brochure.
Likely health risks
Pathogens
Your drinking water supply can become contaminated with harmful microorganisms (or pathogens) including viruses, bacteria and parasites. Generally, these come from human or animal feces, such as contamination from a leaking septic tank and on-site wastewater management system if you have an underground tank. On-site wastewater management systems can also contaminate other water sources (such as a nearby stream or bore) if they’re not properly maintained. Water in irrigation channels and streams can be contaminated with pathogens from run-off from farming activities, making it generally unsuitable for drinking if not properly treated. These pathogens are not visible to the naked eye and may be present in water that appears to be clear. Drinking water that contains pathogens causes gastroenteritis. Children, older people and people with suppressed or weakened immune systems are the most vulnerable to these pathogens. You can reduce the risks by ensuring your drinking water comes from a reliable source and by regularly maintaining your water supply system.
Chemicals
Chemical and heavy metals contaminants can also pose a health risk, although they are usually less common than other contaminants:
- Soil from previous industrial, mining or agricultural activities, which may contain contaminants. Dust can be blown on your roof and washed into your rainwater tank, leading to chemical residues and other contaminants that can build up in the water over time.
- Crop dusting, which can result in agricultural chemicals entering rainwater tanks from roof catchments, irrigation channels, streams and dams.
- Residues from solid wood fired heaters, which can condense near flues on your roof.
- Residue from lead-based paints or lead flashing on older roofs and gutters, which can be washed into your rainwater tank.
- Run-off from roofs in urban or industrial areas, which can contain chemical pollutants from the air.
In some parts of Tasmania, groundwater may contain elevated levels of substances such as arsenic and nitrates. Materials used to manufacture tanks (such as lead solders or non-food grade sealants) can also be harmful to your health.