Research measures potential impacts of fugitive gas emissions on groundwater
By Ground Water Canada
By Ground Water Canada
Vancouver – Researchers have gained valuable insights into the movement and measurement of natural gas in the shallow subsurface, as well as assessments of impacts to groundwater, using a custom-built field station in British Columbia’s Northeast Region.
The Assessment of Fugitive Natural Gas on Near-Surface Groundwater Quality project report published by Geoscience BC examines the physical and biogeochemical processes that impact gas migration and the results provide baseline research needed to support the continuous improvement of BC’s natural gas sector.
“Research like this is valued by industry, governments, communities and Indigenous groups alike. It provides additional knowledge to support decision making about the environment and development,” said University of British Columbia groundwater researcher Bethany Ladd and project lead Prof. Roger Beckie in a news release from Geoscience BC.
Water quality, water quantity and fugitive emissions are three of the four key areas of focus in the provincial government’s 2019 Scientific Review of Hydraulic Fracturing in British Columbia. Recommendations in the report include additional research relating to understanding fugitive emissions, with a focus on field-scale research experiments.
The multi-disciplinary research took place at the Hudson’s Hope Field Research Station 20 kilometres north of Hudson’s Hope in BC’s Northeast Region. In mid-2018, 97.5 cubic metres of a gas mixture mimicking Montney natural gas was released under controlled conditions into the subsurface. Various monitoring methods traced its movement and quantified its environmental effects.
By measuring attributes before, during and for two years after the gas was injected, the researchers found that the majority of the gas remained in the subsurface. Some of the remaining gas migrated to the surface along natural and human-caused pathways, but most was trapped by impermeable layers and dissolved into groundwater.
The current findings suggest that gas migration in the early time after release of natural gas did not lead to degradation of groundwater quality. Based on data from the first two years, the impact on groundwater geochemistry included no significant changes in major or trace elements.