Damn big tank

I know some of you are really broken up about the dearth of construction photos lately, so here's a progress post.
A detention tank is where the storm water goes before being dumped into the storm drain system. It regulates the flow of water so that if we have a big storm, the system doesn't get overloaded with water.
The picture above shows them covering over the building's detention tank with gravel. The gravel is a slightly different color than the dirt, so you can see the extent of the tank. I'll see if I can find the volumetric size, but the description in the documents says 2 tanks, 66" diameter, 78 linear feet each.
You can get a feel for the scale of the project by the munchkins working on the job.


Aileen said...

I'd love to hear more about what you do on a job site. I just love the picture in my head that I have and you marching around checking things out . . .

Anonymous said...

I'm curious as to whether there are joints in it, if it is 70-odd feet long. It must, because if it were all one piece, what vehicle could carry it to the site?
Next question: How do you seal the joints?
Next question: How do you keep it from floating if it is empty and there is ground water?
Next question: Who regulates when to pump it out and when to leave it?
You are right. It is one damn big tank.

Anonymous said...

Our septic tank has roughly the same diameter, and is five feet tall. It holds one thousand gallons. So the tank you describe would hold roughly 12,500 gallons. So it is 25,000 gallons total for both tanks.

belsum said...


Anne C. said...

I don't think it's all delivered in one piece. In fact, I simplified the explanation when I said it was two tanks. It's two tubes connected at both ends. I don't know how the joints are sealed.
If the ground water level was anywhere near the level of the tank, we would not use this type of tank.
The pumps are automatic and are regulated by a fill-level indicator and when it fills faster than it can be pumped out, a second pump starts up. The sizing of the tank and the second pump is based on a "hundred year storm."