Hello Steemians, greetings to you all.
Hope you all are doing well.
Today I'll like to talk about a different method I saw in constructing a Soak away.

Introduction

So I learnt something new and I'll like to share with you all. It's about the Quarry Stone or Hardcore aggregate a larger size of coarse aggregate.

Hardcore or quarry stone is bigger than the regular gravel used in mixing concrete. In proper building construction, the hardcore is placed on the ground before the concrete floor slab. This is to ensure strength and stability of the floor, trap moisture from raising to the ground and also trap noise from objects touching the floor.

In my country, sewage disposal is constructed in each individual building. Often times, the septic tank and the soak away is built together with an internal partition separating the two. The size is usually very large inorder to store waste for longer period of time depending on the number of users. It can be constructed as a rectangle or as a circle.

There's no particular way of building a sewage tank the most important thing is to serve it's purpose. At one of the sites I visited, I observed them dig a small trench (about 7-9 feet deep) compared to the regular deep trench for sewage tank I'm familiar with. The septic tank was dug about 2000meters away from the soak away. I'll not talk about the septic tank but the soak away.

The soak away was dug circularly and the building process started. I wasn't assigned to work there so I do not have documentation of the process. What caught my attention was the arrangement of the hardcore after completion of block work.

Constructing a circular building require high level of technicality to get it right. In constructing a Soak away, spaces are required in between the block at intervals to allow the waste water drain to the soil. As seen in the picture. But the presence of the hardcore makes it even more efficient.

What is the function of the hardcore?

The hardcore used in this case is not for strength but rather acts as a water filter. When liquid waste enters the soak away, the hardcore acts to quickly drain the water to the soil without the soil being too muddy and unable to absorb the moisture.

The spaces in between the block work also by discharging the liquid waste to the soil.
The hardcore all round the soak away serve the same function.

With this technique, it will take a longer period for the waste water to fill up the tank as the process of loosing moisture is more convenient.

So you see, it's not all about the size. The mini size soak away may not get filled up quickly.
Like I said I only picked interest in the construction after it was completed but I did try to draw a section of it.

Sorry I'm a bit impatient with hand drawings especially as I had to imagine the section to recreate that's why I do not have the dimensions.
The wooden members is to construct a formwork for casting the concrete slab.

If there's enough funds and resources, including hardcore or quarry stone in soak away construction will promote longevity and quickly drain moisture.

This construction made me understand other important of coarse aggregate...
I remember a time while growing up. Daddy made a urinary outside the house. He used gravel to cover the soil. As as result the liquid will always drain to the ground without overflowing. Though it turned out to be a bad idea because during the dry season, the stench was unbearable and had to be discontinued.

In summary, laying hardcore on the soil quickly absorb water to the soil compared to pouring the water on the bare soil.

Thank you for reading. I hope you've learnt something new too.