Environmental signatures and effects of an oil and gas wastewater spill in the Williston Basin, North Dakota

Abstract

Wastewaters from oil and gas development pose largely unknown risks to environmental resources. In January 2015, 11.4ML (million liters) of wastewater (300g/L TDS) from oil production in the Williston Basin was reported to have leaked from a pipeline, spilling into Blacktail Creek, North Dakota. Geochemical and biological samples were collected in February and June 2015 to identify geochemical signatures of spilled wastewaters as well as biological responses along a 44-km river reach. February water samples had elevated chloride (1030mg/L) and bromide (7.8mg/L) downstream from the spill, compared to upstream levels (11mg/L and <0.4mg/L, respectively). Lithium (0.25mg/L), boron (1.75mg/L) and strontium (7.1mg/L) were present downstream at 5-10 times upstream concentrations. Light hydrocarbon measurements indicated a persistent thermogenic source of methane in the stream. Semi-volatile hydrocarbons indicative of oil were not detected in filtered samples but low levels, including tetramethylbenzenes and di-methylnaphthalenes, were detected in unfiltered water samples downstream from the spill. Labile sediment-bound barium and strontium concentrations (June 2015) were higher downstream from the Spill Site. Radium activities in sediment downstream from the Spill Site were up to 15 times the upstream activities and, combined with Sr isotope ratios, suggest contributions from the pipeline fluid and support the conclusion that elevated concentrations in Blacktail Creek water are from the leaking pipeline. Results from June 2015 demonstrate the persistence of wastewater effects in Blacktail Creek several months after remediation efforts started. Aquatic health effects were observed in June 2015; fish bioassays showed only 2.5% survival at 7.1km downstream from the spill compared to 89% at the upstream reference site. Additional potential biological impacts were indicated by estrogenic inhibition in downstream waters. Our findings demonstrate that environmental signatures from wastewater spills are persistent and create the potential for long-term environmental health effects.

Shale gas development has limited effects on stream biology and geochemistry in a gradient-based, multiparameter study in Pennsylvania

“…3) illustrates that the composition was less variable during the spring than in the fall, presumably due to the greater influence of dilution with precipitation during the spring compared to the base flow conditions found in the fall. Ratios of Ca, Cl, Li, B, Br, Ba, and Sr concentrations have been described as useful tools for identifying the presence of produced waters in surface waters (24,25,28,29,76,77). In this study, the utility of these geochemical tracers was limited by low occurrence above quantification limits across the study area.…”

“…No significant relationships were found among any of the measured parameters and the sDII categories, although significant seasonal variation was observed. Forty physical and chemical parameters were measured for this study (SI Appendix, Table S5), and, of these, specific conductance (as a proxy for TDS) and dissolved Cl, Br, Ca, Na, Li, B, Ba, and Sr are known as useful geochemical tracers of produced water (24,25,28,29,76,77). The pH was measured as a potential indicator for acids used in shale gas well completion and for potential effects on microbial and macroinvertebrate communities (32,33,48,78).…”

“…waters are highly saline and have a distinct elemental composition in comparison to produced water from younger formations (16,(18)(19)(20)(21)(22)(23). Marcellus Shale-produced waters in north-central Pennsylvania are described as Na−Ca−Cl brines characteristic of evaporated seawater (15,16), have concentrations of total dissolved solids (TDS) in excess of 100,000 mg/L, and contain high concentrations of Na, Ca, Cl, Li, B, Ba, Sr, and Br, which are useful as geochemical tracers for the presence of produced water (24)(25)(26)(27)(28)(29). Streambed sediments have been shown to retain indicators of OG wastes including Ba, Sr, and Ca when there are few detectable geochemical tracers in stream water (25,30); however, few studies have examined bed sediments at a regional scale.…”

Toxicological and chemical studies of wastewater from hydraulic fracture and conventional shale gas wells

“…Chemical mixtures from the wastewater spilled into the environment may be diluted, attenuated by adsorption onto soils, biodegraded, or changed in other ways that alter their composition and possible toxic effects. However, studies such as the present one provide an estimate of impacts in a worse-case spill scenario and, in combination with toxicological and chemical studies of water from actual environmental spills (see Cozzarelli et al 2017;Kassotis et al 2016), provide the beginnings of insight on potential impacts of human exposures to these wastes. These preliminary studies represent a step toward understanding the possible effects to living cells of exposures to chemicals that are added to or mobilized from deep underground during various processes associated with conventional or hydraulic fracturing resource extraction.…”

Groundwater Quality and Hydraulic Fracturing: Current Understanding and Science Needs

“…However, this has created new problems, including induced seismicity triggered by injected wastewater lubricating preexisting, stressed faults (Rubinstein and Mahani 2015). Vehicle accidents during the transport of produced fluids to UIC well sites (Cozzarelli et al 2017), and spills or leakage from careless handling of waste liquids during loading and unloading (Akob et al 2016) also have led to new instances of surface water and groundwater contamination.…”