What resources to look at the minimum depth to prevent underground pipe from freezing (chilled water services with PVC). I am in Enid, Oklahoma. Thank you very much!!!
Check with your local building department. They have codes for minimum clearance for residential water lines that take into account the local frost line.
thien2002,
AWWA D100, the design code for potable water tanks, has a map with required pipe cover depths to avoid freezing. It would seem to be exactly what you are looking for in this case.
In Canada, four (4) feet minimum will clear a guy from the permafrost(lat=54N). The further north, the deeper you need to go. Eventually you'll hit bedrock, the Artic tundra has very little topsoil.
But tell you what, up North, little guys like me can hit a long ball just like John Daley. You get a lot of roll over those outcrops!
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada