Impact of Oil & Gas Wastewater Disposal on Lake and River Sediments

2015年，非常规油气（O&amp；G）井占美国石油产量的1/2以上，天然气产量的2/3以上。非常规油气井产生的废水通常是常规油气井的50 - 60倍。非常规油气开发的增长引发了人们对废水管理可能存在的风险的担忧。一些设施接受O&amp；G废水进行处理，然后将处理后的水排放到溪流中；然而，这些设施可能无法充分去除所有令人担忧的污染物。这项研究将提供证据，证明不适当的废水管理对健康和环境可能造成的不利影响。研究结果有望帮助监管机构和行业改善废水管理策略，防止化学物质进入环境。该项目的目的是确定沉积物记录中的化学特征是否可以用来量化废水处理的历史影响，并评估废水处理污染的沉积物的潜在生物毒性。为实现这些目标，将完成一系列任务。将确定具有大量o&g废水处理和沉积物保留的水动力条件的流域。对于这些水库，将开发沉积物沉积模型来重建沉积物地层，并确定保留连贯时间记录的沉积物采样位置。将组织实地取样活动，从这些地点收集完整的沉积物岩心。岩心处理将产生沉积物和孔隙水的成对样品，作为深度的函数。沉积物年龄将根据210-Pb和7-Be剖面确定。这些岩心中沉积层的物理、化学和毒理学特性将被表征，以识别具有不同o&g化学特征的沉积层。与o&g废水有关的污染物包括盐、碱土金属、天然存在的放射性物质和特种有机添加剂。将对孔隙水样品进行污染指标分析，包括阴离子（Cl, Br, SO4），阳离子（Na, Ca, Ba, Sr, Mg）和微量金属（例如Cd， Cr, As, Pb）。沉积物将被干燥并分析这些相同的元素。虽然主要元素浓度可以表明油气废水的潜在影响，但同位素比率（226-Ra/228-Ra和87-Sr/86-Sr）也可以区分可能的污染源（例如，常规与非常规油气地层水）。沉积物和孔隙水中的有机污染物将通过非目标分析来表征。沉积物的毒性将使用一套基于人类细胞的生物分析方法进行评估。特异性受体将用于检测毒性反应，如DNA损伤、诱导异种代谢、适应性应激反应和激素介导的活性。计划开展外展活动，通过美国化学学会（ACS）科学与大会项目与政策制定者讨论研究结果和影响，通过ACS全国会议的技术会议与科学界讨论，通过阿勒格尼学院K-12教学培训项目与克里克连接的当地学校讨论，并与当地流域团体的公民讨论。

PI Name: William D. BurgosProposal Number: 1703412In 2015, unconventional Oil & Gas (O&G) wells accounted for more than 1/2 of the oil and 2/3 of the natural gas produced in the US. Unconventional O&G wells typically produce 50 - 60 times more wastewater compared with conventionally drilled O&G wells. The growth in unconventional O&G development has raised concerns about possible risks associated with wastewater management. Some facilities accept O&G wastewater for treatment and then discharge the treated water to streams; however, these facilities may not adequately remove all of the contaminants of concern. This study will provide evidence on potential adverse health and environmental impacts resulting from inadequate O&G wastewater management. The results are expected to help regulators and industry improve O&G wastewater management strategies and prevent chemicals from entering the environment.The objectives of this project are to determine if chemical signatures in the sediment record can be used to quantify the historical impacts of O&G wastewater disposal, and to evaluate the potential biological toxicity of sediments contaminated by O&G wastewater disposal. A series of tasks will be completed to accomplish these objectives. Watersheds with significant amounts of O&G wastewater disposal and hydrodynamic conditions for sediment retention will be identified. For these reservoirs, sediment deposition models will be developed to reconstruct the sediment stratigraphy and identify sediment sampling locations that retain a coherent temporal record. Field sampling campaigns will be organized to collect intact sediment cores from these locations. Core processing will yield paired samples of sediments and porewaters as a function of depth. Sediment age will be determined based on 210-Pb and 7-Be profiles. The physical, chemical, and toxicological properties of the sediment layers in these cores will be characterized to identify sediment intervals with distinct O&G chemical signatures. Contaminants of concern associated with O&G wastewater include salts, alkaline earth metals, naturally occurring radioactive materials, and specialty organic additives. Porewater samples will be analyzed for indicators of contamination, including anions (Cl, Br, SO4), cations (Na, Ca, Ba, Sr, Mg), and trace metals (e.g., Cd, Cr, As, Pb). Sediments will be dried and analyzed for these same elements. While major element concentrations can indicate potential impacts from O&G wastewater, isotopic ratios (226-Ra/228-Ra and 87-Sr/86-Sr) that can distinguish possible contaminant sources (e.g., conventional versus unconventional O&G formation waters) will also be measured. Organic contaminants in the sediments and porewaters will be characterized by non-targeted analyses. The toxicity of the sediments will be evaluated using a suite of human cell-based bioanalytical assays. Specific receptors will be used to detect toxic responses such as DNA damage, induction of xenobiotic metabolisms, adaptive stress responses, and hormone-mediated activity. Outreach activities are planned to discuss results and implications of the research with policymakers through the American Chemical Society's (ACS) Science & the Congress program, the scientific community through technical sessions at ACS National Meetings, local schools with Creek Connections -- a K-12 teaching training program at Allegheny College, and citizens in local watershed groups.