Owner system

Septic tank system flushed successfully



A collection of 45,000 septic tanks wouldn’t usually spark excitement, but for Lizzie Johnson and her Healthy Waters team, it was like winning the lottery.

Septic tanks have been known to contaminate Auckland’s waterways and streams for some time, but there was no effective way to monitor the systems.

It took a massive effort to identify them and develop a compliance system to ensure that septic tanks are regularly inspected and maintained.

Launched in November last year, the on-site wastewater compliance system is the first local government system of its kind in New Zealand.

“This system will have a huge impact on our beaches and waterways and on people’s health,” said Lizzie Johnson, senior clean water specialist.

“It gives us more confidence that the septic tanks are properly maintained and if they are not meeting safety standards we can act more quickly to ensure they are fixed.”

The challenge

Most properties in Auckland are connected to the Watercare pipe network and pay for water supply and sewage. But households that are not connected have private septic tanks to treat sewage and other wastewater.

Under Auckland’s unit plan, owners of these properties must provide regular inspection records verifying that their on-site sewage systems are in good working order.

Previously, there was no consistent information on the type, condition, and maintenance history of the septic tanks used. To accurately capture this data, all septic tanks in the region – from Franklin to Rodney and on the Waiheke, Great Barrier and Kawau Islands needed to be located. It took two years to identify all households using septic tanks; data from 45,000 properties was eventually collected and migrated into the new system, along with 9,000 supporting documents.

The research involved:

  • Using the GIS mapping system to identify areas and properties not connected to the main Watercare sewage system
  • Review of construction and resource authorizations
  • Search for emails, manual records and notes
  • Contact owners by mail and visit properties in high-risk catchment areas to request information on their maintenance records.





The second phase is online

An app-based form to facilitate the recording of new data from external contractors who clean and inspect septic tanks for owners was also developed. Information from contractors using the app will automatically update the corresponding property file in the compliance system.

Auckland Council will now start requesting and processing more maintenance records, and creating reports to identify overdue and failed inspections.

“The health of our waterways is vital to Auckland’s future,” says Lizzie. “By giving us accurate and consistent information within hours of an inspection, this system will go a long way in helping us reduce sewage-related public health risks and improve our water quality.”

On-site sanitation compliance is one of five programs funded by the Targeted Water Quality Tariff, which aims to make our ports, beaches and waterways cleaner. Another scheme is the Western Isthmus Water Quality Improvement Project, which reduces sewage overflows into Waitematā Harbor and stormwater into the sewerage system.