Guidance for schools with on-site wastewater systems

Schools with on-site wastewater systems must ensure their systems are maintained to protect public health, the environment and the continued operation of the school. A well-maintained wastewater system helps prevent wastewater overflows, unpleasant odours, groundwater contamination, and costly repairs.

Schools in rural and remote locations may not be connected to a public wastewater network. These schools typically rely on an on-site wastewater system to collect, treat and dispose of wastewater generated from toilets, kitchens, handwashing facilities and other school activities.

Your wastewater system may include:

• a septic tank
• a secondary or tertiary treatment plant
• pumps, filters and control equipment
• a wastewater disposal field, where treated wastewater is safely dispersed into the ground.

Schools should understand:

• the type of wastewater system they have
• where major components are located
• how treated wastewater is disposed of
• servicing and maintenance requirements
• any monitoring or operational requirements specified by the manufacturer.

As a school property owner and operator, you are responsible for ensuring your wastewater system remains in good working order and is maintained in accordance with manufacturer recommendations and relevant regulatory requirements.

You should:

• understand how your wastewater system operates
• arrange regular servicing by a suitably qualified contractor
• maintain records of inspections, servicing and repairs
• promptly address faults or system failures
• protect the wastewater disposal field from damage.

Schools should regularly inspect their wastewater system and surrounding area to identify any signs of potential issues before they become significant problems.

Regular checks

Check for:

• unusual odours around treatment units or disposal fields
• wet, boggy or ponding areas above disposal fields
• warning lights, alarms or equipment faults
• damaged lids, vents or access covers
• overgrown vegetation restricting access to equipment.

Protect your system

To help your wastewater system operate effectively:

• only flush the 3 Ps (pee, poo and toilet paper)
• do not dispose of wipes, sanitary products, fats, oils and grease in drains
• ensure septic friendly cleaning chemicals are used
• report plumbing leaks promptly
• manage water use to avoid excessive loading of the system. 

Healthy bacteria within wastewater treatment systems are essential for effective treatment and can be affected by inappropriate chemicals or materials entering the system. 

All wastewater systems require periodic servicing by qualified service providers (ideally familiar with your wastewater system). Maintenance requirements vary depending on the type of system installed.

Septic tank systems

Schools with a basic septic tank system should arrange regular inspections and pump-outs as required to prevent sludge accumulation and maintain treatment performance. Basic septic tank systems should typically be professionally serviced and pumped out every 3 years, or as recommended by the service provider.

Secondary and tertiary treatment systems

More advanced treatment systems often include pumps, filters and electrical equipment. These systems generally require more frequent servicing in accordance with the manufacturer's requirements.

Routine servicing may include:

• inspecting treatment tanks and chambers
• cleaning pumps and filters
• checking alarms and controls
• identifying blockages or equipment faults
• assessing whether desludging or pump-out is required.

The disposal field is a critical part of the wastewater system. It distributes treated wastewater into the ground for final treatment and disposal.

To protect the disposal field:

• keep vehicles and heavy machinery off the area
• do not construct buildings, playgrounds, courts or hardstand areas over the field
• avoid student and staff access to the area
• avoid stock access where applicable
• maintain grass and vegetation as appropriate
• ensure stormwater is diverted away from the disposal area.

A disposal field that becomes damaged or overloaded can lead to wastewater surfacing, odours and environmental contamination. 

Contact your wastewater service provider if you notice:

• wastewater overflows or backups
• persistent unpleasant odours
• wet or boggy ground around disposal fields
• alarm activations or equipment faults
• unusually lush or overgrown vegetation over disposal areas
• visible wastewater reaching drains, waterways or neighbouring properties. 

Prompt attention to small issues can help avoid major repairs, disruption to school operations, system replacement costs and environmental impacts.

Schools should maintain records of:

• servicing and inspection reports
• pump-out records
• repairs and upgrades
• manufacturer maintenance recommendations
• fault investigations and corrective actions. 

Maintaining accurate records supports compliance, assists future maintenance planning and may be a requirement if your system is subject to a resource consent.

Some school wastewater systems operate under a resource consent issued by the relevant regional or unitary council. These consents may include conditions that specify how the system must be operated, maintained and monitored.

If your school has a resource consent, it's important that you understand and comply with all consent conditions. These conditions may include requirements for:

• routine servicing and maintenance
• system monitoring and sampling
• reporting to the council
• record keeping
• management plans or operating procedures.

Schools should ensure resource consent documentation, monitoring requirements and compliance records are retained and made available to relevant staff and service providers.

If you're unsure whether your wastewater system is subject to a resource consent, contact your local council or Property Advisor.

Schools that treat and dispose of wastewater on-site may be eligible for reimbursement of costs associated with operating and maintaining their wastewater systems, including:

• servicing
• maintenance
• repairs
• monitoring
• sampling, and
• testing.

These costs are generally reimbursed through the Ministry of Education's heat, light and water (HLW) funding self-supply one-off cost reimbursement process.

Heat, light and water funding – Ministry of Educationopen_in_new

Where significant repairs, upgrades or replacement of wastewater infrastructure are required, schools should contact their Property Advisor to discuss available support and funding options.

For advice or support on managing an on-site wastewater system, contact the New Zealand School Property Agency Water Services team at water.services@school.property.govt.nz.