Know your onsite wastewater system

Buying or building a rural or semi-rural property? Make sure you know where the wastewater goes.

Living outside of a main population centre often means not only sourcing your own drinking water, but also finding a safe way to treat and dispose of household wastewater.

Most towns and cities have their drinking wastewater managed through reticulated systems, which are paid for through rates. But many semi-rural and rural properties are not connected to wastewater networks. 

If you are able to connect to a wastewater network, it's your responsibility to do so, but if not, you'll have some type of onsite wastewater management system (OWMS), or will need to have one installed as part of a build.

While many OWMS can be installed and operated as a permitted activity, some require resource consent – particularly when located close to other dwellings, drinking water sources or sites with environmental or cultural values.

Visit the dedicated wastewater section of our website for guidance on the types of OWMS, consenting requirements and maintenance advice.

There you can find more information about the different types of wastewater treatment system, the Permitted Activity rules under which these systems can operate without resource consent, more tips for maintaining your wastewater treatment system, and a guide to buying or selling property with a wastewater treatment system.

Wastewater treatment

The most common system for single households is a septic tank and land application system, but there are a range of different primary and secondary treatment systems available.

While systems can differ in design and capacity, they all serve the same purpose – ensuring that wastewater is managed effectively to prevent degrading water quality, which can lead to significant cultural impacts and affect local drinking water supplies and the local environment.

Maintaining your wastewater treatment system

Leaky and poorly maintained systems can allow improperly treated wastewater to escape into the nearby environment – potentially endangering your health.

Most systems will require a regular inspection and maintenance at least every 12 months, and primary treatment systems like septic tanks will need to have sludge and scum pumped out around once every three years.

However, if you notice an issue – like a sewage overflow, murky or smelly puddles around your treatment system, or even a broken tank lid – you should get your system inspected immediately by a suitably qualified technician.

Buying or selling land or property

Before you buy a property or piece of land you intend to build on, check if it’s connected to a reticulated wastewater system – usually owned and operated by the local council.

If it’s not and there is an existing onsite wastewater management system, you’ll need to check with a lawyer or estate agent whether it is consented, and how it's been operated and maintained.

If there is no onsite wastewater management system, you'll have to determine whether you can meet Permitted Activity rules or require resource consent.