Skating is a fantastic winter activity but keep the rink away from your leaching bed.
Leaching beds are carefully built to accept water -- even if it is an excess amount coming from a hose sprayed in the middle of winter. We know those who have managed to freeze their entire leach field solid, and ended up with wastewater backing up into the house.
Not only rinks, do not build decks, patios or place above ground pools in or over your leaching bed.