Groundwater Use Map for NC (IMAGE) Duke University Caption Areas of the North Carolina with the largest number of groundwater users, like Wake and Mecklenburg Counties, coincide with some of the highest probabilities for finding hexavalent chromium above state health advisory levels (red). Credit Rachel Coyte, Duke Univ. Usage Restrictions Please Use Credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.