Here is the place to control the foam particles' lifetime and behaviour.
Surface offset
With 0.0, particles are created directly at the fluid's surface, but you can also define an offset between the core fluid and the splashes. This distance is measured in metres.
...
If you want to destroy the particles after a certain time then you can define a lifespan with “Foam min | max lifetime”. The actual lifetime will be somewhere between both values, and this value defines the upper limit. The value is given seconds.
...
Min friction
This value specifies the minimum amount of the grid fluid’s velocity that will be transferred to the foam particle. 1.0 means that the entire velocity is transferred and the foam particles are stuck to the grid fluid. With 0.0 the foam particles are not affected. If you use different values for the min and max parameters the actual friction will be somewhere between both settings.
...
Max friction
This value specifies the maximum amount of the grid fluid’s velocity that will be transferred to the foam particle. 1.0 means that the entire velocity is transferred and the foam particles are stuck to the grid fluid. With 0.0 the foam particles are not affected. If you use different values for the min and max parameters the actual friction will be somewhere between both settings.