Recent advances in shale gas development have largely outpaced efforts to manage associated waste streams that pose significant environmental risks. Wastewater management presents significant challenges in the Marcellus shale, where increasing fluid volumes concomitant with expanding development will threaten to overwhelm existing infrastructure over the next decade. In this work, we forecast growth in drilling, flowback, and produced fluid volumes through 2025 based on historic data and consider conventional and alternative disposal options to meet future demands. The results indicate that nearly 12 million m3(74 MMbbl) of wastewater will be generated annually by 2025. Even assuming wastewater recycling rates in the region rebound, meeting increased demands for wastewater that cannot be reused due to poor quality or logistics would require significant capital investment to expand existing disposal pathways, namely treatment and discharge at centralized facilities or dedicated brine injection in Ohio. Here, we demonstrate the logistical and environmental advantages of an alternative strategy: repurposing depleted oil and gas wells for dedicated injection of wastewater that cannot otherwise be reused or recycled. Hubs of depleted wells could accommodate projected increases in wastewater volumes more efficiently than existing disposal options, primarily because the proximity of depleted wells to active production sites would substantially reduce wastewater transport distances and associated costs. This study highlights the need to reevaluate regional-scale shale wastewater management practices in the context of evolving wastewater qualities and quantities, as strategic planning will result in more socially and economically favorable options while avoiding adverse environmental impacts that have overshadowed the environmental benefits of natural gas expansion in the energy sector.
This content will become publicly available on February 1, 2025
Treated water from oil and gas extraction as an unconventional water resource for agriculture in the Anadarko Basin
the central United States, PW disposal occurs through deep well injection, which can increase seismic activity.
The treatment of PW for use in agriculture is an alternative to current disposal practices that can also provide
supplemental water in regions where limited freshwater sources can affect agricultural production. This paper
assesses the potential for developing PW as a water source for agriculture in the Anadarko basin, a major oil and
gas field spanning parts of Kansas, Oklahoma, Colorado, and Texas. From 2011 to 2019, assessment of state oil
and gas databases indicated that PW generation in the Anadarko Basin averaged 428 million m3/yr. A technoeconomic
analysis of PW treatment was combined with geographical information on PW availability and
composition to assess the costs and energy requirements to recover this PW as a non-conventional water resource
for agriculture. The volume of freshwater economically extractable from PW was estimated to be between 58
million m3 per year using reverse osmosis (RO) treatment only and 82 million m3 per year using a combination of
RO and mechanical vapor compression to treat higher salinity waters. These volumes could meet 1–2 % and
49–70 % of the irrigation and livestock water demands in the basin, respectively. PW recovery could also
modestly contribute to mitigating the decline of the Ogallala aquifer by ~2 %. RO treatment costs and energy
requirements, 0.3–1.5 $/m3 and 1.01–2.65 kWh/m3, respectively, are similar to those for deep well injection.
Treatment of higher salinity waters increases costs and energy requirements substantially and is likely not
economically feasible in most cases. The approach presented here provides a valuable framework for assessing
PW as a supplemental water source in regions facing similar challenges.
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- Award ID(s):
- 1856084
- PAR ID:
- 10505363
- Editor(s):
- Ouyang Wei
- Publisher / Repository:
- Elsevier, Science of the Total Environment
- Date Published:
- Journal Name:
- Science of The Total Environment
- Volume:
- 912
- Issue:
- C
- ISSN:
- 0048-9697
- Page Range / eLocation ID:
- 168820
- Subject(s) / Keyword(s):
- Produced water Irrigation Livestock watering High Plains aquifer High-salinity wastewater
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract -
Produced water (PW) is the largest waste stream associated with oil and gas (O&G) operations and contains petroleum hydrocarbons, heavy metals, salts, naturally occurring radioactive materials and any remaining chemical additives. In some areas in Wyoming, constructed wetlands (CWs) are used to polish PW downstream of National Pollutant Discharge Elimination System (NPDES) PW release points. In recent years, there has been increased interest in finding lower cost options, such as CWs, for PW treatment. The goal of this study was to understand the efficacy of removal and environmental fate of O&G organic chemical additives in CW systems used to treat PW released for agricultural beneficial reuse. To achieve this goal, we analyzed water and sediment samples for organic O&G chemical additives and conducted 16S rRNA gene sequencing for microbial community characterization on three such systems in Wyoming, USA. Three surfactants (polyethylene glycols, polypropylene glycols, and nonylphenol ethoxylates) and one biocide (alkyldimethylammonium chloride) were detected in all three PW discharges and >94% removal of all species from PW was achieved after treatment in two CWs in series. These O&G extraction additives were detected in all sediment samples collected downstream of PW discharges. Chemical and microbial analyses indicated that sorption and biodegradation were the main attenuation mechanisms for these species. Additionally, all three discharges showed a trend of increasingly diverse, but similar, microbial communities with greater distance from NPDES PW discharge points. Results of this study can be used to inform design and management of constructed wetlands for produced water treatment.more » « less
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Increasing soil salinity and degraded irrigation water quality are major challenges for agriculture. This study investigated the effects of irrigation water quality and incorporating compost (3% dry mass in soil) on minimizing soil salinization and promoting sustainable cropping systems. A greenhouse study used brackish water (electrical conductivity of 2010 µS/cm) and agricultural water (792 µS/cm) to irrigate Dundale pea and clay loam soil. Compost treatment enhanced soil water retention with soil moisture content above 0.280 m3/m3, increased plant carbon assimilation by ~30%, improved plant growth by >50%, and reduced NO3− leaching from the soil by 16% and 23.5% for agricultural and brackish water irrigation, respectively. Compared to no compost treatment, the compost-incorporated soil irrigated with brackish water showed the highest plant growth by increasing plant fresh weight by 64%, dry weight by 50%, root length by 121%, and plant height by 16%. Compost treatment reduced soil sodicity during brackish water irrigation by promoting the leaching of Cl− and Na+ from the soil. Compost treatment provides an environmentally sustainable approach to managing soil salinity, remediating the impact of brackish water irrigation, improving soil organic matter, enhancing the availability of water and nutrients to plants, and increasing plant growth and carbon sequestration potential.
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null (Ed.)The decreasing cost of electricity produced using solar and wind and the need to avoid CO 2 emissions from fossil fuels has heightened interest in hydrogen gas production by water electrolysis. Offshore and coastal hydrogen gas production using seawater and renewable electricity is of particular interest, but it is currently economically infeasible due to the high costs of ion exchange membranes and the need to desalinate seawater in existing electrolyzer designs. A new approach is described here that uses relatively inexpensive commercially available membranes developed for reverse osmosis (RO) to selectively transport favorable ions. In an applied electric field, RO membranes have a substantial capacity for proton and hydroxide transport through the active layer while excluding salt anions and cations. A perchlorate salt was used to provide an inert and contained anolyte, with charge balanced by proton and hydroxide ion flow across the RO membrane. Synthetic seawater (NaCl) was used as the catholyte, where it provided continuous hydrogen gas evolution. The RO membrane resistance was 21.7 ± 3.5 Ω cm 2 in 1 M NaCl and the voltages needed to split water in a model electrolysis cell at current densities of 10–40 mA cm −2 were comparable to those found when using two commonly used, more expensive ion exchange membranes.more » « less
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While development of the Utica/Point Pleasant Shale (UPP) is extensive in Ohio (U.S.) and increasing in Pennsylvania and West Virginia, few studies report the chemistry of produced waters from UPP wells. These data have important implications for developing best management practices for handling and waste disposal, or identifying the fluid in the event of accidental spill events. Here, we evaluated the elemental and isotope chemistry of UPP produced waters from 26 wells throughout Ohio, Pennsylvania, and West Virginia to determine any unique fluid chemistries that could be used for forensic studies. Compared to the Marcellus, UPP produced waters contain higher activities of total radium ( 226 Ra + 228 Ra) and higher 228 Ra/ 226 Ra ratios. As with the Marcellus Shale, elemental ratios (Sr/Ca) and isotope ratios ( 87 Sr/ 86 Sr) can distinguish UPP produced waters from many conventional oil and gas formations. Sr/Ca and 87 Sr/ 86 Sr ratios can fingerprint small fractions (∼0.1%) of UPP produced water in freshwater. However, because Marcellus and UPP produced waters display similar major elemental chemistry ( i.e. , Na, Ca, and Cl) and overlapping ratios of Sr/Ca and 87 Sr/ 86 Sr, 228 Ra/ 226 Ra ratios may be the best tracer to distinguish these waters.more » « less
