The AES System

The AES Wastewater Treatment System

AES (Advanced Enviro-Septic™) is a high quality, reliable, cost competitive, environmentally sustainable, maintenance- free on-site wastewater treatment system that will save you money.

Features & Benefits

Exceptional Quality of Treatment

  • Highest secondary treatment levels – treatment results are 10 times better than Aus/NZ Standard 1547 for Secondary Treatment when tested at NZ’s OSET-NTP.
  • AES achieves very high pathogen reduction, without using disinfection such as UV filters or chlorination.

A Silent, Reliable System

  • Noise-free without pumps or alarms.
  • Maintenance-free. No regular checks needed by homeowners or plumbers. Just empty the septic tank when needed.
  • Power-free

Fit and Forget

  • No electronics or moving parts to replace – i.e pumps, control boards, aerators or blowers.
  • No membranes or replacement media to clean and replace.
  • No chemicals to add.
  • Just empty sludge from the septic tank every 5-7 yrs as for any septic system.

Advantages over other Systems

Cost Savings

  • Over $1,000 annual savings – in power costs, servicing contracts, filters, membranes, additives or chemicals.
  • No costly annual maintenance contracts. Most councils require homeowners to have their septic system serviced at least every 6 months. This is not required with the AES system.
  • No pump to replace at minimum $1,000.

Natural Treatment, Safe for the Environment

  • No added chemicals
  • AES uses natural biological processes to treat effluent.
  • The high quality of treatment and long life of the system protects groundwater from contamination and minimises risk of health issues.
  • Local – AES uses local installers, locally sourced septic tanks and locally sourced system sand.


  • No worm casts to dispose of every 6 months.
  • No need to restock worms when they die.

Design Flexibility

  • AES installations are adaptable to many site conditions with various design options available.
  • AES systems can be used for greywater only, blackwater only and combined all‐waste systems. Treated effluent can be collected and used for irrigation.
  • An AES treatment bed can be straight or curved (up to 90 degrees), follow contours or fit around objects
  • AES can be installed under driveways.
  • For areas with high groundwater AES can be installed in a raised bed.
  • Treatment beds can be landscaped with grasses or other shallow rooting plants.
  • AES can be installed in new projects or retrofitted to an existing septic tank to upgrade to secondary treatment.

Proven Long Life & International Reputation

  • AES components are extremely durable and last indefinitely. An AES system will keep on working for you. Systems unearthed after 15-20 years have been shown to be functioning as installed with clean, unclogged sand beds.
  • 20-year warranty on components – longer than any other system.
  • Premier system worldwide. AES systems have been installed in the USA, Europe, Australia, South Africa and many other countries for over 25 years with long-lasting and reliable results.
  • Rigorous testing in North America, Europe, Australia and NZ shows consistently high quality results.

Systems Comparison

AES compares very favourably with other on-site wastewater treatment systems.

How On-site Septic Treatment Works

There are 3 levels of on-site septic treatment.

Primary Effluent Treatment
Raw effluent flows from a building or ablution block into a septic tank. Here, initial treatment is anaerobic (without air) as microbes in the effluent consume some of the suspended organic material. Inorganic material settles to the base of the tank and a scum layer floats on the surface sealing the majority of the effluent off from the air within the tank. Overflow from this tank is disposed of into a bed in the ground.

Secondary Treatment
Secondary effluent treatment is often a council requirement, and treats effluent to a higher level. Secondary treatment may be required when the disposal bed following primary treatment is on too small an area of land, is close to surface water or there is concern about groundwater contamination. Secondary treatment involves aerobic (in the presence of air) microbes resulting in the almost complete removal of dissolved and suspended organic matter from the effluent.

Dispersal to Ground
After these treatments, the effluent is usually required to be dispersed to a bed in the ground where soil bacteria and microbes in the soil consume whatever nutrients are left.

How AES works

AES onsite wastewater treatment system - how it works

AES is a passive, on-site advanced secondary wastewater treatment system developed and in use in the USA for over 25 years with over 500,000 installations. Gravity fed from a septic tank, effluent is treated using naturally occurring microbes within specially designed, passively aerated pipes laid in a sand bed.  The remaining highly-treated effluent is evenly dispersed via perforations in the AES pipes into the sand bed or can be collected and used for irrigation if preferred. Within the sand bed, there is further microbial breakdown.

The key to the success of the AES system is passive ventilation through specially designed AES pipes which provide an environment for the microbes in the effluent to be processed to a safe level. A standard AES system does not require pumps, filters or any maintenance. All that’s required is a routine septic tank pump-out every 5-7 years. AES is simple, using the processes of nature, environmentally sustainable and very effective.

The essential AES treatment process occurs in specially designed, 300mm diameter, oxygenated pipes installed in a sand bed in the ground. Effluent flows via gravity into the AES pipe system from the septic tank and is exposed to a culture of naturally occurring microbes that break down solids and digest potential organic pollutants more rapidly in the presence of air. Based on a ‘chimney’ effect, air is drawn into a low-level inlet vent at one end of the system of AES pipes and naturally flows through to a high-level vent at the other end.

AES pipes

AES pipes have been especially designed in the USA. A mat of coarse, random fibres completely covers the pipes providing additional surface area for the microbial breakdown of solids and bacteria to take place. Skimmers on the interior capture grease and suspended solids from the effluent. Bio-Accelerator™ fabric at the base of the pipe facilitates the development of a biofilm of self-colonising microbes that process the organic material. By reducing permeability this biofilm also ensures the effluent extends the entire length of the pipe.

AES wastewater treatment system

Why AES is the best system by David Presby, inventor of AES

Part one
Part two

Steps to get an AES system

  • Step 1 to get an AES system
  • Step 2 to get an AES system
  • Step 3 to get an AES system

Our team can answer any questions you have about the AES combined treatment and dispersal system and how it will fit your site.

We can give you a ballpark cost and organise an on-site assessment for a wastewater design by one of our accredited AES designers in your area.

The AES designer will visit your site and in conjunction with you determine the best placement of the system in relation to property, boundaries, water sources, your soil category, underground water table etc., and in accordance with NZ standards and your local council rules.

From this, the AES Designer will create a design report for inclusion with your building consent application.

Environment Technology peer reviews the AES design for your added confidence.

With approved consent, the installation can proceed. You can either call us and we will arrange for a price/s from local AES certified plumber/drainlayer installers, or your preferred drainlayer can become AES certified by completing our free online training course.
The installer will arrange for the purchase and delivery of AES components and the supply of a locally produced septic tank. They assemble the components and install the system as designed.

Your AES system will immediately start functioning. You can relax knowing there is a 20-year warranty on all AES components, and no need for maintenance contracts, regular inspections, or cleaning of filters.

Technical Advice and Quality Assurance

Environment Technology, NZ-wide distributors of the AES system, provide free technical advice and peer review 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 20-year warranty on all AES components provides peace of mind.

The NZ test results at OSET-NTP in the table on the right speak for themselves.



AES System Design

AES System Installation

No. After system sand is spread between rows we recommend that the installer straddle each row of pipe and walk heel-to-toe its entire length, ensuring that system sand fills all void spaces beneath and between the AES pipes. Pneumatic-tyred equipment and/or mechanical compactors should not be used to compact system sand, backfill or fill extension areas. Mechanical compaction will damage the soil’s ability to disperse liquid and may inhibit air supply to the entire system.
Yes. Glueing is highly recommended to ensure connections remain assembled during the backfill procedures.
No. During installation, the fabric will typically reach or cover part of the fitting. We recommend sandwiching the white accelerator fabric within the coupling if possible. If the fabric falls short of reaching the fitting, it is no cause for alarm. Installers can very easily pull or push the pipe to make it slightly longer or shorter. If space remains between the fabric and fitting, the system sand will bridge over-exposed pipe perforations, preventing additional system sand from entering the pipe and suspended solids from exiting the pipe.