This report covers tests and criteria for the establishment of safe grounding systems for coal mines. The work deals primarily with underground mines, but much is applicable to surface mines as well. Included is an extensive guide to grounding and bonding procedures for mine surface substations. Xit-rods (chemically charged, hollow- rod electrodes that generate their own moisture and metallic salts and uses the resulting electrolyte as the interface medium between the conducting surface of the rods and outwardly in the soil and lowers resistance) are evaluated and shown to deviate from manufacturers claims. An analysis shows that very long cables are difficult to monitor using audiofrequency ground-check techniques. A method is developed to detect failing cable splices without removing the cable from service. Simulation and measurement are compared for a technique to detect bad rail bonds, and an assessment is made of grounding techniques for DC face equipment.