37 Miss. Code R. § 1-7501-04015-901
Pipelines, multiple ducts, rigid conduits, telephone cables and like underground structures shall have a minimum cover of thirty six (36) inches. All encasements and carrier pipes will also have a minimum cover of thirty six (36) inches. Underground installations will be covered additionally as required to protect them from damage by heavy maintenance equipment or other apparent hazards. In special circumstances where required depth of cover cannot be obtained. Other means for obtaining protection of an appropriate design and approved by the Department, may be required. Generally, construction and design requirements will comply with the regulations of the Mississippi Public Service Commission and/or with the current Standard Code of Pressure Piping of the American National Standards Institute.
37 Miss. Code. R. § 1-7501-04015-901