Not so Hazardous Water
According to the USGA, “‘Casual water’ is any temporary accumulation of water on the course that is not in a water hazard and is visible before or after the player takes his stance. Snow and natural ice, other than frost, are either casual water or loose impediments, at the option of the player. Manufactured ice is an obstruction. Dew and frost are not casual water.”
“A ball is in casual water when it lies in or any part of it touches the casual water.”
According to rule 25-1 without penalty the player can lift and drop the ball within one club length of the nearest point of relief. Whenever you can see standing water under your feet or your ball you are allowed free relief at the nearest point where there is no standing water but the relief also has to be no closer to the hole.