IEEE Standard 80-1976 is primarily concerned with ground gradient of substation installations. Large industrial petrochemical plants demand bulk power supply from substations and, coupled with cogeneration plants, make the design of the grounding system rather complex and costly due to high ground fault currents. The basic design criteria in grounding are clarified and a step-by-step procedure in designing a safe and economical ground grid for such plants is provided.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>