top

Flood-prone septic tanks pose significant health risks


28 July 2020

Water New Zealand says effluent leakages from flooding and poorly maintained septic tanks pose a major health risk to the community.

Recent flooding in Northland has led to raw sewage from septic tanks spilling into parks and a local school playground.

Water New Zealand CEO, Gillian Blythe says this is a major health risk and shows the need for better septic tank monitoring and risk assessment.

“There are around 270,000 private onsite wastewater management systems and septic tanks throughout the country servicing about 20 percent of the population.”

She says owners need to be more aware of the potential risk for contamination of local waterways as well as private drinking water wells.

“In many cases there is no ongoing monitoring of septic tanks, so it is left to owners to ensure their units are well maintained and functioning properly.

“The risks increase dramatically when there is flooding as water can flow into the tank and spill raw sewage into the environment.

“After a flood there is a need to not only clean up the immediate spillage but also ensure that any damage to the surrounding soak area has been repaired.

She says councils need to identify septic tanks, especially those prone to flood risk and to work with owners to raise their awareness to help reduce risk of environmental contamination.”

Water New Zealand recently produced a domestic users’ guide for homeowners of septic tanks and on-site wastewater management systems.

Go here to download the guide. 

Click to listen to Water New Zealand's chief executive Gillian Blythe speak to Māni Dunlop on RNZ regarding the matter.