Answer
Pile is about $7.52ft$ high.
Work Step by Step
The diameter and height have constant connection, which means that for any given time if height = $h$ diameter is $3h$. So, the radius of conical pile is $1.5h$
Volume of a cone is:
$V=\frac{\pi r^2 h}{3}$
$1000=\frac{\pi \times 2.25h^2 \times h}{3}$
$3000=2.25\pi h^3$
$h^3\approx 424.41$
$h\approx 7.51501\approx 7.52ft$
