The slope length is calculated using the Pythagorean Theorem, where the vertical distance is the rise and the horizontal distance is the run: rise2 + run2 = slope length2.
Example: If a water sampler was placed at a vertical distance of 10 feet and a horizontal distance of 20 feet from a water source, the equation would be solved like this:
102 + 202 = slope length2
100 + 400 = slope length2
500 = slope length2
√500 = slope length
≈22.36 feet = slope length
In this example, the facility would need more than 22 feet of tubing to cover the distance from the water sampler to the water source.
Note: A minimum tubing length of 25 feet is recommended for a vacuum pump sampler.