A Houston Chronicle investigation from reporter Amanda Drane found an expanding pool of evidence suggesting oil wells are coming unplugged. Some call them "Zombie Wells," and they're compounding the already challenging problem of hundreds of thousands estimated orphaned wells that, in some cases, have been left unplugged for decades. 

Unplugged wells and those with failing plugs allow climate-warming gasses and toxic waters to freely rise to the surface, poison groundwater aquifers and kill plants.

The problems caused by leaking wells can be expensive to fix, and the longer an old well sits, the more the steel casing and cement protecting the hole degrade. The problem can be exacerbated by wastewater flowing underground. Some od wells that deteriorated could cost as much as $1 million to fix.

In the three part series, Drane explores how these issues are coming into sharper focus as the energy industry dives into uncharted territory with carbon capture and storage, perceived by many as pivotal in the fight against climate change. Operators would remove climate-warming carbon dioxide from the air and pump it underground for storage, yet unplugged and leaking wells pose a risk for the future of the emerging industry because they could allow carbon dioxide to travel back to the surface. That in turn, could undo climate benefits and endanger humans. 

Read the entire article - Zombie Wells