The decommissioning of half of Pole 1 and the operational restrictions placed on the remaining Pole 1 capacity led to the HVDC link operating mostly in monopolar mode, using Pole 2 alone. In 2010, Transpower reported that continuous operation in monopolar mode has caused the HVDC link to act as a galvanic cell with the earth, causing Benmore's Bog Roy earth electrodes to erode as they acted as an anode, and causing the buildup of magnesium and calcium hydroxide deposits on Hayward's Te Hikowhenua shore electrodes as they acted as a cathode. Additional replacement and maintenance work was required.