"A new University of Waterloo report warns that natural gas seeping from 500,000 wellbores represent 'a threat to environment and public safety' due to groundwater contamination, greenhouse gas emissions and explosion risks wherever methane collects in unvented buildings and spaces.

The 69-page report on wellbore leakage cowritten by three expert UofW professors outlines a longstanding and largely invisible engineering problem for Canada's oil and gas industry.

It also calls for dramatic reforms in monitoring and regulation including greater engineering oversight of the cementing of wellbores and 'doing it right in the first place.'"

Andrew Nikiforuk reports for The Tyee June 5, 2014. [2]