Grooves in a Concrete Pad for an AST

[chicopee]

A newly installed 20,000 gallons vertical tank on a two foot thick reinforced concrete slab. Concrete slab is square and roughly 25'X 25'.Two perpendicular grooves,(about 2"X2")running from opposite edges and thru the center the concrete slab were incorporated. I have never seen such large grooves in CB's before. Are these grooves for "telltale" about potential tank bottom leak or are these for crack control?

 

[IFRs]

They are telltales.

 

[chicopee]

Thanks IRF

 

[11echo]

FYI - "IF" this foundation had a high point in the center, when a leak did occur you could pin-point the leak origin to a quadrant in the tank.

 

[chicopee]

At least pinpoint which half of the bottom is leaking but not whereabout.