Passive intake screens are stationary screening cylinders positioned in a water body so as to take advantage of ambient currents and controlled through-screen velocities to minimize debris buildup. Passive screens are usually mounted on a horizontal axis and oriented parallel to the ambient currents that provide necessary cleaning action. A radial well intake is an infiltration system that utilizes slotted pipes or screens placed horizontally in a naturally occurring sand or gravel aquifer. The intake is constructed by installing a vertical caisson below the water table near a river or creek with radial wells jacked out into the surrounding aquifer. Water enters the system through the screen pipes and empties into the central caisson where it is removed by pumping. Radial well intake systems have the environmental advantage of segregating the marine life populations from direct contact with the screen mechanism or screen structure.