Acute toxicity of sodium bicarbonate, a major component of coal bed natural gas produced waters, to 13 aquatic species as defined in the laboratory

Abstract

Water produced during coal bed natural gas (CBNG) extraction in the Powder River Structural Basin of Wyoming and Montana (USA) may contain concentrations of sodium bicarbonate (NaHCO3) of more than 3000 mg/L. The authors evaluated the acute toxicity of NaHCO3, also expressed as bicarbonate (HCO3(-)), to 13 aquatic organisms. Of the 13 species tested, 7 had a median lethal concentration (LC50) less than 2000 mg/L NaHCO3, or 1300 mg/L HCO3(-). The most sensitive species were Ceriodaphnia dubia, freshwater mussels (Lampsilis siliquoidea), pallid sturgeon (Scaphirhynchus albus), and shovelnose sturgeon (Scaphirhynchus platorynchus). The respective LC50s were 989 mg/L, 1120 mg/L, 1249 mg/L, and 1430 mg/L NaHCO3, or 699 mg/L, 844 mg/L, 831 mg/L, and 1038 mg/L HCO3(-). Age affected the sensitivity of fathead minnows, even within life stage. Two days posthatch, fathead minnows were more sensitive to NaHCO3 and HCO3(-) compared with 4-d-old fish, even though fish up to 14 d old are commonly used for toxicity evaluations. The authors recommend that ion toxicity exposures be conducted with organisms less than 24 h posthatch to ensure that experiments document the most sensitive stage of development. The results of the present study, along with historical and current research regarding the toxicity of bicarbonate, may be useful to establish regulatory standards for HCO3(-). This article is a US Government work and is in the public domain in the USA.

Effects of environmentally relevant mixtures of major ions on a freshwater mussel

“…Recent studies have documented the toxicity of HCO 3 À to aquatic organisms, with toxic effects to freshwater mussels occurring at NaHCO 3 concentrations >900 mg/L Harper et al, 2014). The mechanism for HCO 3 À toxicity is thought to involve interference with ion exchange via Na þ /K þ -ATPase and the HCO 3 À /Cl À co-transporter Harper et al, 2014). However, sublethal concentrations of HCO 3 À can lessen the toxicity of Cu to freshwater organisms (Daly et al, 1990;Hyne et al, 2005;Wurts and Perschbacher, 1994).…”

“…Major differences in water chemistries between the current study and the 10% stream water treatments in Kunz et al (2013) are pH (8.4e8.8 in the current study and 8.1e8.3 in Kunz et al (2013)), and HCO 3 À (110e229 mg/L in the current study and 102e135 mg/L in Kunz et al (2013), calculated from reported alkalinity). Recent studies have documented the toxicity of HCO 3 À to aquatic organisms, with toxic effects to freshwater mussels occurring at NaHCO 3 concentrations >900 mg/L Harper et al, 2014). The mechanism for HCO 3 À toxicity is thought to involve interference with ion exchange via Na þ /K þ -ATPase and the HCO 3 À /Cl À co-transporter Harper et al, 2014).…”

Toxicological perspective on the osmoregulation and ionoregulation physiology of major ions by freshwater animals: Teleost fish, crustacea, aquatic insects, and Mollusca

“…Elucidation of the details of this mechanism are needed because HCO 3 − ranked relatively high among the major ions in terms of toxicity [128]. Moreover, HCO 3 − is a primary constituent of produced waters from coalbed natural gas development and effluents from mountaintop mines and valley fills [304,305,322]. …”

“…Although they did not investigate the physiological mechanisms, Harper et al [304] assessed the toxic effects of NaHCO 3 as a major constituent of produced waters from coalbed natural gas wells. The 96-h LC50 values for the larval stages (1–22 d posthatch [dph]) of white sucker ( Catostomus commersonii ), fathead minnow, walleye ( Sander vitreus ), rainbow trout, and northern pike ( Esox lucius ), respectively, were estimated as 13.6 mM, 38.5 mM, 58.9 mM, 93.4 mM, and 131.1 mM NaHCO 3 .…”

“…Using absence of foot movement during a 5-min observation as the indicator of mortality, the 96-h LC50 and 7-d LC50 for juveniles were 13.8 mM and 12.6mM NaHCO 3 , respectively [304,305]. …”