Background: My 20x40 size NJ pool pumps and filter were behind my pool at the bottom of a slope and retaining wall.  The dirt slopes 30 -35 degrees from the pavered pool deck to the 4 ft retaining wall for a distance of 4 feet. The lines would come through the retaining wall to the system about 1 ft from the base.  To winterize, I lowered the pool level below the skimmer, Polaris and return ports and had an electric heat wire wrapped around the main drain line (which I was always leary of, but worked).  A tree fell and broke the lines during the winter.  After repairing, there was a leak coming through the retaining wall from the main drain line.  After plugging the drain, disassembling part of the retaining wall and much digging, I found the leak was a disconnected joint (presumably due to freezing/contraction) about 3 feet in from the retaining wall and about 3 feet below ground. So,not the worst scenario.

Question: So,now I am in the process of moving the pumps and filter above grade and away from any trees.  Now that I have the main drain line exposed, I want to be smart about winterizing.  I've read about pumping air through the line until the drain bubbles and closing the line.  But in addition to that, I thought if I could put a valve with an actuator underground (remember 3ft in and 3 ft under; well buffered, but not completely safe form freezing), I could remotely close the line there to prevent water from seeping past that point and give me some peace of mind about potential freezing.  Nothing I have read about the actuators has described an underground installation.  I also don't want to install a control system, such as the AquaLink® RS control system.  I can run the wires as I am rerouting the water lines.  I just want to be able to flip a switch to close the valve.  So, what are your thoughts/concerns?