We are replacing our galvanized water lines with cpvc. As part of the project, we also moved the washer dryer to the garage which entailed running an ABS drain line to the main sewer line. We are using the same trench to bring the water line from the main shut-off into the house. We had planned to run the water line underground and bring it up at the back end of the garage (the garage is attached to the front of the house).

I've read the code book and in the only section I found that speaks to a sewer line and water line sharing the same trench, it does not say that you have to follow any rules so long as your water and sewer materials are approved. Because our main sewer line is so shallow, we are running the water line lower than the sewer line and it actually crosses under at two points. Is this okay to do?

Second question--Can we run the cpvc underground all through the garage or do we have to go up as soon as we enter the structure?

Thanks for your help.