Concrete pour - water cleanliness question

[RDrancher]

I made my living as a residential/commercial concrete contractor in SoCal for over 25 years. I poured over 250 yards for tower pads at the top of Mt. Wilson in the mid-eighty's. Due to the remote location, all of the loads were shipped dry. Water was added onsite from tanks fed by cisterns...all rainwater. The tanks were slimy with algae. The job was for the Navy, so you can bet that there were a few inspectors onsite. I know that some of you will find this very hard to believe but.....the concrete is still there and the towers haven't fallen over!

That said...I would probably pour the water through a screen into the mixer to filter the big stuff out. If you don't want to use rebar, at the least pull the mesh up as you place the concrete.

 

[GPintheMitten]

I looked at one of the links you posted. I see there is a picture of alligators in a pond. I can't read so I assume it means to filter all alligators out of the water. No.pictures of frogs, so apparently frogs are ok.

 

[ultrarunner]

The local ready mix plant drilled a well because of drought restrictions on municipal water.

The well had plenty of water that could not be used based on analysis...

 

[breadtrk]

I'm waiting for the drinking water guys to explain the rusty, slimy, concrete truck water tank that every truck on the planet is hauling the mix water in.......

 

[roadhunter]

I'm waiting for the drinking water guys to explain the rusty, slimy, concrete truck water tank that every truck on the planet is hauling the mix water in.......

This^^. People who think that water is clean enough to drink are sadly mistaken.

To the OP. Don't sweat it. The water you describe is easily just as clean as what many concrete trucks carry to jobsites every day.

 

[alchemysa]

'Potable' means 'drinkable'. There are many aspects to what makes water drinkable but in this case it probably simply refers to the salt content. (The intent being that you do not use very salty water to make concrete). Recommended maximum ppm for drinkable water is 1000ppm. Most town water is about 50 to 400 ppm. Bore water in our area is about 600ppm.

Its highly unlike that any rainwater stored as per the OP's method will be much more than 50 ppm if that. The water in our rainwater tank is only about 10ppm.