Produced Water Spills Related to Unconventional Oil and Gas Development in North Dakota

Abstract

Beginning in 2007 unconventional oil production increased dramatically in the region of North Dakota overlying the Bakken shale formation. Since, the North Dakota Department of Health has reported more than 4,000 accidental spills of produced water. Our study seeks to follow up on a 2016 study by Nancy Lauer et al., which characterized the major and trace element chemistry of 29 surface waters in areas impacted by oil and gas wastewater spills. Comparing to background levels and the composition of Bakken produced waters, we used conservative element chemistry characterized 33 surface water samples sites impacted or potentially impacted by produced water spills, including 6 sites sampled the year before. Soil and sediment collected from the sites analyzed for total radium activities (228Ra & 226Ra) showed persistent contamination. One of the most heavily affected sites, an 11 million gallon spill near Blacktail Creek, that was characterized the year before experienced extensive remediation and displayed much lower levels of contaminants in 2016. However, this site was an anomaly; other sites continue to display persistent inorganic contamination up to 5 years after the initial spill.