Is the NIBW cleanup causing land subsidence?
No. However, Motorola has investigated the potential for land subsidence in the NIBW Site and area to the north. Over the last 50 years this area has been extensively pumped by a number of water providers and groundwater levels have declined as much as 300 feet, increasing the risk of subsidence. The Arizona Department of Water Resources has indicated there is no evidence of land subsidence within the NIBW Site. However parts of North Scottsdale, North Phoenix, and Paradise Valley, in the area north and northwest of the NIBW Site, have documented land subsidence. According to reports issued by the City of Phoenix Engineer’s Office, more than seven feet of subsidence and earth cracks have been observed in the vicinity of two COP municipal well fields where past pumping caused groundwater levels to decline more than 300 feet.
