Elizabeth McGowan, Lisa Song and David Hasemyer are the three reporters from InsideClimate News, the online non-profit magazine on environmental sciences, nuclear energy and clean energy, to win this year’s Pulitzer Prize in the National Reporting section, which every year pays tribute to the best reporting on national events.

The prize has been awarded to the team from the Brooklyn-based environmental magazine for “The Dilbit Disaster: Inside the Biggest Oil Spill You’ve Never Heard Of”, a rigorous report on flawed regulation of the nation’s oil pipelines, focusing on potential ecological dangers posed by diluted bitumen (or “dilbit“), a controversial form of oil.

The project began with a seven-month investigation into the million-gallon spill of Canadian tar sands oil into the KalamazooRiver in 2010. It broadened into an examination of national pipeline safety issues, and how unprepared the nation is for the impending flood of imports of a more corrosive and more dangerous form of oil.

We’ve brought the term “dilbit” into the national panorama of energy information,” said David Sassoon, publisher of InsideClimate News. “It’s important to know that this is a different type of oil with different implications for energy policy and climate change.” The recent ExxonMobil pipeline spill in Arkansas and the debate over the controversial Keystone XL pipeline (see also here) underscore the continuing relevance of this ongoing body of work.

It goes without saying, this is “a good day for environmental journalism and a hopeful signal for the future of our profession,” adds David Sasoon.