Is your rainwater tank summer-ready?

Sunshine Coast Hospital and Health Service

Summer in our region means sun, sand, surf… and storms and bushfires. Is your rainwater tank summer-ready and safely maintained?

Residents are urged to keep their rainwater tank safe this summer with regular, effective maintenance.

Sunshine Coast Hospital and Health Service Manager Environmental Health Greg Bennett said using rainwater tanks involved low maintenance, not no maintenance.

“Like all drinking water supplies, rainwater systems need to be monitored; and the associated maintenance is not too onerous, but it is necessary,” Mr Bennett said.

“Monitoring your rainwater tank is an important responsibility, consisting of a range of visual inspections rather than laboratory testing of rainwater quality. Maintenance is needed to maintain good water quality and prevent mosquitoes breeding.”

Here are the top monitoring and maintenance activities that will help you keep your rainwater tank system safe:

• Clean gutters (six-monthly and after storms)
• Clear first flush device of debris (monthly and after storms)
• Check for evidence of animal, bird or insect access (six-monthly)
• Check roof and gutters for accumulated debris including leaf and other plant material (six-monthly)
• Check and trim overhanging branches (six-monthly)
• Inspect and repair downpipes, check condition of the roof (six-monthly)
• Check tanks for sludge accumulation (at least every two to three years). If sludge is covering the bottom of the tank, siphon it out or completely empty the tank. Professional tank cleaners operate in many areas.
• Prevent tanks and gutters from becoming breeding sites for mosquitoes by insect screening.

“Rainwater is generally safe to drink providing it is clear, has little taste or smell, and is from a well-maintained system. However reticulated or ‘town’ water provides the safest and most reliable source of drinking water,” Mr Bennett said.

“Queensland Health recommends that residents should use town water supplies for drinking, personal hygiene and food preparation if they live in areas that have access to these supplies.”

Mr Bennett said that for most people, especially those who had been drinking rainwater for most of their lives, there would be very little health risk in drinking rainwater, provided the rainwater collection and storage system was well maintained.

“However, there are some members of the community for whom microorganisms (such as bacteria) when present in rainwater could pose health risks, including infants, the elderly and immune-compromised people such as transplant, dialysis, HIV or cancer patients with severely weakened immune systems,” Mr Bennett said.

“These people should consider disinfecting the water before drinking or cooking with it. You can do this by boiling the water.”

Rainwater may be used without further treatment for flushing toilets, the cold water laundry tap and for watering gardens and lawns as these uses generally present a low risk of disease.

Bushfires and roof harvested rainwater

Bushfires produce large amounts of smoke, ash and debris that can settle on roofs used to collect rainwater.

Before a bushfire

Residents who live in bushfire-prone areas should consider installing a system whereby the pipes that direct the water from the roof to the rainwater tank(s) can be disconnected quickly and easily. This will prevent any material deposited onto the roof surface, as a result of a bushfire, from entering the rainwater tank. The disconnection should be made as soon as the threat of a bushfire is apparent to prevent windblown debris entering the tank and so that evacuation (if required) is not hampered. It may also be worthwhile sealing the openings to the tank to prevent contamination.

After a bushfire

If the rainwater tank has not already been disconnected from the collection pipes, disconnect or redirect the pipes as soon as it is safe to do so. Once this step has been completed, then clean the roof and gutters thoroughly. Cleaning the roof and the gutters with water that is known to be safe is likely to be the most effective way of removing ash and other contaminants that might be present (don’t use a pressure washer if you have an asbestos roof). Once the roof and gutters have been cleaned, the pipes that direct water to the tank can be reconnected. Ensure the first flush device, if installed, is empty and in good working order.

If it has rained since the bushfire, and before the collection pipes have been disconnected or redirected, it is likely that ash and other contaminants will have flowed into the tank. In most cases, this will mean that the tank will need to be drained and cleaned (note that the water drained from the tank(s) may be used for non-drinking uses, e.g. watering the garden, dust suppression). Once the tank has been drained and cleaned, it should be refilled with water from a source known to be safe for drinking. If the bushfire has damaged the integrity of the tank, it is likely that the tank will require draining and repair or replacement. Take care working around rainwater tanks that have been damaged by a bushfire.

For more information call Gympie Regional Council or visit www.health.qld.gov.au