Water treatment plants are designed and built to process a specific amount of water, within a specific range of raw water qualities with a predetermined finished water quality. These are called design parameters or values.

The water operator should be aware of the design values for their plant for the sedimentation and clarification process. Using organisational procedures as a guide, water operators are required to manage the processes to ensure that actual operating values are as close to the design values as possible.

Water operators can make a number of calculations to check the current operating effectiveness of the sedimentation and clarification processes.

These calculations are based on the incoming flow rate and known values about the treatment.

Therefore, it's important to monitor the current operating status of the plant. In large, modern plants this will often be carried out by a SCADA or other control system. However, an operator should be able to carry out a few basic calculations to check this independently.