Perhaps your local utility requires a second meter, if so you're stuck with it. However, here's how my city work it. One meter which is read during the dead of winter to establish my household usage which also determines my sewer rate. From the meter, I come with 1" copper then a tee. One branch goes straight to the house for household use. This is 5 feet below ground level. The second branch has a stop and waste valve then is elbowed up toward the surface. Just below the surface in a utility control box is my back flow preventer. From the preventer, I elbowed down about a foot or so and then this line runs to the manifold for the irrigation system. In the fall, I just turn the stop and waste off, remove the preventer (unions on both sides). I attach my air compressor to the sprinkler line, open one zone at a time, and blow the lines. Having 2 meters is really a waste of money unless required by local authorities. Well, it still would be a waste, but you can't fight city hall!