There’s Instantaneous Bathing Load and There’s Daily Bathing Load. They’re Not the Same Thing.


It’s important not to overload a pool with pollution. Since bather are the main source of pollution, the numbers using the pool on a daily basis should be controlled.

In order to calculate the total daily bather load the following formula should be used:

25 to 50% of the instantaneous bather load multiplied by 12.

As an example, for a pool with an instantaneous bather load of 110:

  • 25% of 110 = 27.5 x 12 = 330
  • 50% of 110 = 55 x 12 = 660

Daily bather load will be 300 to 660 bathers per day.

This information should then be recorded in the Normal Operating Procedures (NOP).