I have successfully blown out all my sprinkler zones and have nothing but air coming through all the heads. However, the service line bringing water from the street meter to my back flow valve is still full of water. How do you winterize this line? It's all below ground, besides the last 8 inches that come above ground to tie in to my backflow preventer. Does this line need to be winterized? How? Currently, I have an insulated bag over it, with a decorative rock cover over that. Thank you, Scott
