To properly design a grounding system and meet the standard requirements, the soil resistivity shall be tested before installing the ground electrode system. It is also recommended to test the resistivity such as when expanding a building, adding significant amounts of electronics or telecommunications. If the resistivity is too high, this may indicate that more ground electrode system Is required. It is also recommended that some maintenance or inspection procedure be adopted by ground resistance testing or earth impulse impedance testing to ensure the effectiveness of grounding system