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Wastewater math

Tank Area Formulas for Wastewater Operators

The area of rectangular and circular tanks.

The formula

Formulas

  • Rectangle area

    Area = length × width

    WPI Formula/Conversion Table (2023), Printed page 1 of 10, Area of Circle and Area of Rectangle

  • Circle area from diameter

    Area = 0.785 × diameter²

    WPI Formula/Conversion Table (2023), Printed page 1 of 10, Area of Circle and Area of Rectangle

  • Circle area from radius

    Area = π × radius²

    WPI Formula/Conversion Table (2023), Printed page 1 of 10, Area of Circle and Area of Rectangle

Open the Formula Sheet→

Worked example

Step by Step

A rectangular basin floor is 15 ft long and 9 ft wide. What is its surface area?

  1. Known Values

    Length is 15 ft and width is 9 ft.

  2. Find

    Find the two-dimensional surface area in square feet.

  3. Identify the Shape

    The surface is a rectangle.

  4. Choose the Formula

    Area = Length × Width

  5. Put In the Values

    15 ft × 9 ft

  6. Check the Units

    Feet times feet gives square feet (ft²).

  7. Answer

    135 ft²

Answer: 135 ft²

Practice

Try It Yourself

Practice this math in the Math Center, with hints and worked steps.

Practice Area / VolumeLearn the Pie Wheel

More formulas

Other Wastewater Math

  • Detention Time Formula
  • Pounds Loading Formula
  • Chemical Feed Rate Formula
  • Percent Removal Formula
  • Channel Flow Rate Formula
  • MGD to GPD Conversion

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