EVALUATING THE RISKS OF SURFACE SPILLS ASSOCIATED WITH UNCONVENTIONAL OIL AND GAS ACTIVITY TO GROUNDWATER RESOURCES: A MODELING STUDY FOR THE SOUTH PLATTE ALLUVIAL AQUIFER

Surface spills occur frequently during unconventional oil and gas production operations and have the potential to impact groundwater quality. A screening-level analysis using contaminant fate and transport simulations was performed to: (1) evaluate whether hypothetical (yet realistic) spills of aqueous produced fluids pose risks to groundwater quality in the South Platte Aquifer, (2) identify the key hydrologic and transport factors that determine these risks, and (3) develop a screening-level methodology that could be applied for other sites and pollutants. This assessment considered a range of representative hydrologic conditions and transport behavior for benzene, a regulated pollutant in production fluids. Realistic spill volumes and areas were determined using publicly available data collected by Colorado’s regulatory agency. Risk of groundwater pollution was based on predicted benzene concentrations at the groundwater table. Results suggest that the risk of groundwater contamination from benzene in a produced water spill was relatively low in the South Platte Aquifer. Spill size was the dominant factor influencing whether a contaminant reached the water table. Only statistically larger spills (volume per surface area ≥12.0 cm) posed a clear risk. Storm events following a spill were generally required to transport typical (median)-sized spills (0.38 cm volume per surface area) to the water table; typical spills only posed risk if a 500 or 100 year storm (followed by little degradation or sorption) occurred right after the spill. This methodology could be applied to evaluate spills occurring over other aquifers.

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EVALUATING CONTAMINATION POTENTIAL OF SURFACE SPILLS ASSOCIATED WITH UNCONVENTIONAL OIL AND GAS DEVELOPMENT ABOVE AN ALLUVIAL AQUIFER

10.1130/abs/2017am-305999 ◽

2017 ◽

Author(s):

Cynthia Kanno ◽

◽

John E. McCray

Keyword(s):

Oil And Gas ◽

Alluvial Aquifer ◽

Oil And Gas Development ◽

Unconventional Oil ◽

Unconventional Oil And Gas

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Groundwater resources monitoring during unconventional oil and gas extraction: South African laboratory analytical capabilities

Water SA ◽

10.17159/wsa/2021.v47.i3.11859 ◽

2021 ◽

Vol 47 (3 July) ◽

Author(s):

Azwifaneli Mulovhedzi ◽

Surina Esterhuyse

Keyword(s):

South African ◽

Groundwater Monitoring ◽

Oil And Gas ◽

Groundwater Resources ◽

Policy Recommendations ◽

African Region ◽

Resource Quality ◽

Unconventional Oil ◽

Unconventional Oil And Gas ◽

Analytical Requirements

Groundwater resource quality monitoring before, during, and after unconventional oil and gas (UOG) extraction would assist in protecting groundwater resources. Limited laboratory analytical capacity may, however, hamper effective monitoring. We assessed South African (SA) laboratory analytical capabilities for specific groundwater monitoring parameters relevant to UOG extraction. We found a limited capacity to analyse for most of the UOG extraction–related groundwater monitoring parameters and that most of the surveyed laboratories are not planning to increase their analyses capacity to cater for UOG extraction. This issue must be addressed urgently if SA wants to proceed with UOG extraction. Policy recommendations include that South Africa should develop a specialised UOG extraction monitoring laboratory to cater for analytical needs. Such capacity could also address the analytical requirements for the rest of the African region during UOG extraction.

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