This Question was asked the other day during a training presentation to a Local Authority Plumbing Team with a lot of experience, questions and problem applications.

“Is a designer expected to learn all this in one training Session? “

The Answer is, “ NO”

It is an important aspect of the overall development of Advanced Enviro-septic that the opportunity for continuous ongoing development is presented at design stage by our AES calculator approval process. As you would be aware every AES calculator is submitted to for checking to ensure that we achieve the best possible outcome from the Advanced Enviro-septic or simply advise that it will not fit.

We recently received an AES calculator for a domestic installation from an Engineer that had designed 2 systems previously. I have attached our communication to the engineer to show how every AES design is an opportunity for continuous ongoing development of our AES knowledge and application with in the industry.

Shared with permission from the recipient.


Hello Henry,

Your calc was correct for the design as drawn. I have marked up a couple of things. When you have a toe it is our preference that it remain in the natural soil. We always like to see the drawings of the system pipes to accurately match the number of pipes.

IE 4 pipes in each row. (As a plumber I know that we prefer to look at pictures 1st)

It is also good to provide a mow-able swale above the AES or cut of drain if deemed necessary. In poor soils like this site, the top 150mm is the better quality and can become saturated and conduct water downhill. The shallow swale helps to intercept this flow and protect the land application area.

I also marked up the system plan to match the attached calculator using the trench extension option. This reduces the pipe and trench required to the AES pipes. It also allows for better distribution along the full trench when there are peak loads (wash days etc.) It also saves 1 lth of pipe. You could either cut a pipe to create 2 equal runs or have 5 lths in the1st part and 4 in the second part. (Preferred.) Again important that you’re drawing clearly shows the pipe segments in the plan.

The infiltration footprint is always level in a trench extension design. See also attached lineal loading for different configuration.

The attached Calculator has been changed to use the trench extension option. The difference to yours is that you had used the trench option to force the system width 3.36 with a standard parallel pipe configuration. So I am not sure if you had a site restriction on the 30m lth. The trench extension option I used is 3 meter. You can change this if you need to keep it at 30mtrs as the pipe lth + inline adaptor and 300mm each end gives a lth of 27.8 m.

By entering 1 row in the number of rows data field the calculator configures for a single run.

Give me a call if you would like to discuss.