There are several important factors to consider here.
Detention time should be provided to cause the well cuttings and solids to drop out of the flow. For wells being drilled at construction sites, this can be accomplished by excavating a shallow trench, 10-15 feet long, immediately downgrade of the well. The downstream edge of the trench should be level to allow water to spill out uniformly over the entire length of the trench. A semi-circle of silt fence or straw bales should be installed downgrade of the trench for further sediment removal.