The menacing presence of petroleum coke in Detroit raised a fair amount of concerns about the environment and health in recent months.

Mayor Dave Bing's office on Thursday proclaimed that concern history.

He said the mounds of petroleum coke along the Detroit Rivers are now gone, according to a report in the Detroit News by Jim Lynch. The materials are a byproduct of the oil refinery process and can be used for fuel.

Lynch reports the product was created by Marathon Oil Refinery in Southwest Detroit, and purchased by Koch Minerals LLC.

If that name Koch sounds familiar, well, yes it's the very famously rich Koch brothers who have campaigned over time for many anti-liberal causes. -- Allan Lengel

Read more: Detroit News