One advantage is having redundancy within the system. If one pump malfunctions, there is a back-up to keep the system operational. Another advantage to having multiple pumps is the ability to cycle the operation of each pump to reduce wear and allow for maintenance to be conducted during off periods. For cost saving measures, larger pumps can sometimes be replaced with multiple smaller pumps to handle the same amount of flow. This is not always applicable but it can be a better option for the same redundancy reasons. Multiple pumps also give the system the ability to handle a wider range of flow rates in a more efficient manner. If the system sees dramatic swings in peak inflow due to seasonal weather or other reasons, then the system could run on one pump for part of the year and then run the second and/or third pump for periods of greater flow.