GSA Annual Meeting in Denver, Colorado, USA - 2016

Paper No. 90-6
Presentation Time: 9:55 AM

UNCONVENTIONAL OIL AND GAS (UOG) WASTEWATER SPILLS: PERSISTENCE OF CONTAMINANTS AND ENVIRONMENTAL HEALTH IMPLICATIONS


COZZARELLI, Isabelle M.1, KENT, Douglas B.2, CROTEAU, Marie-Noele3, SKALAK, Katherine J.4, BENTHEM, Adam5, ENGLE, Mark A.6, MUMFORD, Adam C.7, AKOB, Denise M.8, FARAG, Aida M.9, HARPER, David D.9, OREM, William H.10 and HAASE, Karl B.11, (1)U.S. Geological Survey, U.S. Geological Survey MS 431, Reston, VA 20192, (2)U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025, (3)U.S. Geological Survey, 345 Middlefield Road MS 496, Menlo Park, CA 94025, (4)U.S Geological Survey, 430 National Center, Reston, VA 20192, (5)U.S. Geological Survey, National Research Program, 430 National Center, Reston, VA 20192, (6)Eastern Energy Resources Science Center, U.S. Geological Survey, MS 956, 12201 Sunrise Valley Dr., Reston, VA 20192, (7)National Research Program, Eastern Branch, U.S. Geological Survey, Reston, VA 20192, (8)U.S. Geological Survey, National Research Program, Eastern Branch, 12201 Sunrise Valley Dr, Reston, VA 20192, (9)U.S. Geological Survey, Columbia Environmental Research Center, Jackson Field Research Station, P.O. Box 1089, Jackson, WY 83001, (10)Eastern Energy Resources Science Center, U.S. Geological Survey, 12201 Sunrise Valley Dr, MS 956, Reston, VA 20192, (11)US Geological Survey, Mail Stop 432, 12201 Sunrise Valley Drive, Reston, VA 20192, icozzare@usgs.gov

UOG wastewaters that contain toxic and radioactive elements from geologic formations, or chemical additives from production, pose largely unknown impacts to water resources, aquatic ecosystems, and human health. In North Dakota alone, over 8,000 recorded spills from 2008-2015 included over 20-mill gal of waste fluids. As part of a national study of the impacts of UOG activities, USGS researchers are conducting interdisciplinary studies in regions of active UOG development, including the Williston Basin, ND. In Jan. 2015 an estimated 3 mill gal of wastewater brine (TDS 138 g/L) from UOG production spilled into Blacktail Creek, a tributary of the Missouri River.

Water and sediment samples were collected, and in situ bioassays were conducted, along a 44 km reach between the spill and the Missouri River in Feb and June 2015 and June 2016, to assess potential impacts from the spill. Wastewater in the ruptured pipeline contained 16.2 mg/L Ba and > 1,000 mg/L Sr. Samples collected in June 2015, indicate presence of UOG-wastewater markers and biological impacts in the river. These results document the persistence of geochemical alterations six months post spill. Fish bioassays conducted in June, 2015, demonstrated 97.5% mortality at 7.1 km downstream from the spill.

Alterations in sediment microbial communities downstream from the spill were observed in February 2015. Labile Ba and Sr concentrations extracted from sediments collected in June 2015 were higher downstream from the spill site than upstream. Radium concentrations in sediment downstream from the spill site (approx. 10 dpm/g) were up to 5 times the background concentrations. Ra and Sr isotope ratios in sediment downstream from the spill site resemble the radiogenic signatures from the pipeline and support the conclusion that elevated Ra and Sr concentrations reflect input from the spilled wastewater brine.

Experiments with an aquatic model invertebrate, the freshwater snail Lymnaea stagnalis, showed aqueous Ba is bioavailable and thus will bioaccumulate. Ba has deleterious effects on aquatic organisms and humans and a similar reactivity to Ra, providing insight into Ra pathways through the food chain. Partitioning of elements from the wastewater spill onto sediment limits aqueous transport but could provide a long-term source to aquatic ecosystems.