AES (Advanced Enviro-Septic™) is a reliable, cost-competitive, high quality, environmentally friendly, and maintenance-free sewage system that will save you thousands over a lifetime.

How it Works

AES is a passive, onsite wastewater treatment system developed and in use in the USA for 30 years with over 500,000 installations. Gravity feeding from a septic tank, effluent is treated using natural bacterial processes within specially-designed, passively aerated pipes laid in a sand bed.  The treated effluent is dispersed passively into the soil beneath the bed, or can be collected and used for irrigation if preferred.

For more detailed information go to How it Works or download our Brochure.

Why install an AES Wastewater Treatment System?

  • AES is accepted by all NZ Councils (most as a secondary system) and achieved excellent treatment outcomes at the premier testing facility for wastewater treatment systems, OSET-NTP in Rotorua. AES systems are installed in the USA, Europe, Australia, South Africa and many other countries with long-lasting and reliable results.
  • AES provides 10x the results recommended by the AUS/NZ Standards without the use of power or chemicals providing a cleaner output into groundwater resources and soil.
  • Cost competitive to install or retrofit to an existing septic tank for secondary treatment, and adaptable to site conditions.
  • No need for costly annual maintenance contracts. Only need to have the septic tank pumped out when it’s full, every 6-7 years.
  • Safe for your Environment – Protects the ground water by high quality treatment and long life. Treatment beds can be landscaped with grasses or lawn and placed out of sight.
  • Treated effluent can be used for irrigation.
  • 20 year warranty


Our team can answer any questions you might have regarding the system and your specific site. We can give you a ballpark cost assessment and provide you with the names and contact details of AES certified wastewater designers in your area.

Your wastewater designer will visit your site and determine your soil category, water table and best placement of the system in relation to property, boundaries, water sources etc, according to NZ standards and the rules of your local Council. From this assessment, the AES Designer will create a report which will include the AES Design, AES Design Calculator and Site Plan.

Your designer sends their wastewater report to Environment Technology for peer review. Once approved by ET, the report is digitally signed and returned to the designer who provides this to you. You then submit the report to your local Council along with your consent application.

Once your consent application has been approved, you can arrange for the AES system to be installed by a local drainlayer.
You can either:
a) Get in touch with ET and we will put you in touch with a local certified AES installer; or
b) Ask your preferred drainlayer if they are a certified AES installer. If they aren’t they can do our free online training course to become certified. Please note that they must be a licensed NZ drainlayer.
Your AES installer can provide an estimate for the cost of installation based on the report from your AES Designer. The installer will contact Environment Technology to arrange the purchase and dispatch of AES components. The drainlayer will install the system arranging for the required Council inspections.

Once installed, the standard AES system has no ongoing costs and no maintenance requirements! The only thing requiring your attention will be the routine de-sludging of the septic tank to be undertaken once every 6 or 7 years. Our 20 year warranty also gives you peace of mind.

Useful Links

Technical Advice and Quality Assurance
Environment Technology who supply the AES system in New Zealand, provide technical advice and sign off on all designs for Council submission. All AES system Designers and Installers need to have completed the Environment Technology free online Certification Course which provides comprehensive information and training on the design and installation process.

The OSET-NTP test results in the right hand column below speak for themselves.