Understand how surface water is getting into our drains

Our Gerry explains how surface water is getting into our drains and overwhelming our sewage systems. 

"Millions and millions of litres of rainwater and surface water from a storm and rains would break up any treatment plant and overwhelm it."

See a written explanation below.

In the video above Gerry shows us how much water just disappears down through a badly sealed manhole cover to the sewers. 

"Maybe you’ve noticed these inspection chambers around your property. They may be different. They’ve got different types, but the one you need is a double-sealed cover and frame, which seals it from or doesn't allow the rainwater to ingress. 

I'll tell you why. Because if these drains lead to the sewers in the main road, and in turn, the sewers take it to a private treatment plant or public treatment works it disrupts the whole process involved in treating the wastewater that is supposed to be there. What they have is a holding tank, and this holding tank is where the solids and unwelcome fats are separated from the fluid which then proceeds to the treatment section. 

But if this rainwater gets into the system by indirect means or direct means it will destroy the actual process of separation in the holding tank. The sewage water is not settled in any way, shape or form. You would need a tank five times the size or so to handle this rainwater. 

Using a half-inch hose – I filled up a two-litre bottle and allowed this water, as well as the hose water to keep pouring on top of this inspection cover. The two-litre bottle of water only takes a few seconds to drain through the cracks. 

So imagine if it was raining – chucking it down with rain and really a big downpour. The water would stand proud on this patio for a while. Half inch 50 millimetres above the inspection chamber. So then how much water is disappearing down these unsealed lids?

So imagine if a downpipe from the roof of a house is connected directly to the sewer system. You can only imagine what's going to happen. In heavy rain or storms, the separation will be disrupted on an enormous scale.”

Gerry also shows us how the process of separation works with a simple home experiment using a jug of water containing food waste, oils and fats.

“Most of the solids within a minute, two minutes at most five minutes sink to the bottom, and the unwanted fats float to the top. This separation leaves a middle section with comparatively clean water. This then flows through to the next chamber where further treatment occurs.

Millions and millions of litres of rainwater and surface water from a storm and rains would break up any treatment plant and overwhelm it.

And then eventually because of that, the waste would be pushed through and discharged into our rivers. It goes into our streams and into the land itself. But eventually, rainwater from storms or heavy rain. It goes into the sea via the public sewer networks, and you can't really blame them because our houses and properties have been plumbed that way!”