The passage describes a snowmaker company put in many snow-making-machines and man-made lakes to insure Sochi has enough snow at the course to hold the Winter Olympic games. The following "system" is referred to the snow-making-machine.
You're in the mountains so you play with Mother Nature and you deal with what she's giving you. The system is designed around having extremely marginal conditions, not normal conditions, but extremely marginal conditions.
What does the term "marginal conditions" mean here? Is it a technical term?