"P2906.4.2 Underground non-metallic water service piping shall be made detectable by the installation of tracer wiring that complies with Public Utilities Article, § 12-129 of the Annotated Code of Maryland.
P2906.4.2.1T he wire shall be an insulated copper tracer wire suitable for direct burial, at least 10 AWG, or equivalent. Insulation shall be 30 mil minimum thickness, HMWPE or HDPE polyethylene, and color-coded blue. The wire shall be installed in the same trench as the piping, tied or taped to the pipe every S to 8 feet in the 3 o'clock position or installed within 12 inches of the pipe in fill. One end of the wire shall terminate within five feet of the building served, at or above grade, accessible for use, and resistant to physical damage.
P2906.4.2.2T racer wiring installations shall be tested by location with line tracing equipment upon completion of rough grading and again prior to final acceptance."
Md. Code Regs. 09.20.01.03