Introduction

A workshop on ‘Building Knowledge for Environmental Assessment of CO₂ Storage: Controlled Releases of CO₂ and Natural Releases Workshop’ was held in July 2012 hosted by Montana State University (MSU) in Bozeman, Montana. This workshop focussed on controlled release projects. As such, it brought together for the first time most of the world’s controlled release projects, ten in number. This created the opportunity not just for sharing of results, but for future sharing of facilities and techniques, opportunities which were taken advantage of during the meeting.

The workshop also looked at the Environmental Assessments undertaken for real projects, with details being provided by Shell on the Quest project and its recent approval.

In the area of monitoring, great progress is being made. There are increased capabilities and new experiences offshore. The very realisable capability for large-area monitoring was shown, with the potential capability of leak detection, and work on offshore baselines also being ground-breaking. Exciting developments in onshore monitoring were also presented, including the Process-based technique, for assessing the source of CO₂ found in the near-subsurface.

One of the concluding recommendations was to “Keep up the good work” because gaps identified in the previous two workshops are being successfully addressed. The meeting concluded with a request from participants to become a full IEAGHG Network, called the “Environmental Research into CO₂ Storage Network”.

The third workshop in an IEAGHG series on environmental impact assessment of CO2 storage was held in July 2012. The ‘Building Knowledge for Environmental Assessment of CO₂ Storage: Controlled Releases of CO₂ and Natural Releases Workshop’ was held from the 17^th to 19^th July 2012 in Bozeman, Montana. It was hosted by Montana State University (MSU) and sponsored by MSU, Southern Company and the Center for Advanced Energy Studies. Forty-eight delegates attended from 12 countries.

The main focus of this workshop was on controlled release projects with other sessions on environmental impact assessments and Regulations, monitoring, overburden/ mechanisms of migration from deep to shallow subsurface, leakage scenarios and communication of leakage. The third day of the meeting was spent at Yellowstone National Park, with part of the day observing formations created from natural CO₂ seepage.

Key Points

• EIA regulations are not a barrier to projects

• There are now a good number of controlled release projects, providing useful knowledge

• CO₂ release behaviour in the near-subsurface can be unpredictable

• Marine work – very good progress on monitoring and on baselines

• Electro-magnetic remote monitoring of brine appears very useful for ‘early’ leakage detection

• Environmental Assessments will be substantially different for offshore to onshore, we don’t have offshore examples yet

• If leakage does occurs –it will be ‘patchy’ and in small localised areas, not over a  large area

• The Process-based technique is an example of monitoring moving in right direction – able to provide important information where there are no baselines. This technique uses ratios of gases present to determine source of CO₂

• Still need baselines for leakage detection and impact assessment

• Indicator species are being identified, especially benthic and terrestrial plants

• Seasonality and timing can effect leakage impact

• Broader acceptance of near-surface monitoring then in 2008