The City of Burlington operates multiple groundwater wells to provide drinking water to its citizens and visitors. Burlington is required by the Colorado Primary Drinking Water Regulations, Regulation 11, to collect routine samples from each well providing drinking water. One of the parameters for which the samples are analyzed is nitrate. Water sample results for Well Number 7 which were received Friday, March 28, 2014, showed nitrate levels of 10.2 milligrams per liter (mg/L). Water sample results for Well Number 9 which were received Friday, March 28, 2014, showed nitrate levels of 13.7 milligrams per liter (mg/L). These results are above the nitrate maximum contaminant level (MCL) of 10 mg/L. Upon notification of the high nitrate level in Wells Number 7 & 9, Burlington officials took the wells offline and ceased pumping water from them on March 28, 2014.