The Department of Defense (DoD) has put out an open call on the Small Business Innovation Research (SBIR) program website in search of proposals regarding an environmentally friendly way to deal with spent training rounds.

In the posting, the DoD notes that the US Army manufactures and subsequently fires hundreds of thousands of training rounds at multiple ranges around the world. Such rounds range from 40mm grenades and 120mm mortars to shoulder-launched munitions and 155mm artillery rounds.

The projectiles and sometimes even the cartridge casings are either left behind on the surface of the ground or become embedded several feet in the earth. Unfortunately, the material used to create the spent casings and projectiles can take hundreds of years (or more) to break down naturally. Some even have the potential to corrode and pollute nearby water and soil.

As it stands today, there’s no easy way to go about finding and removing the discarded materials. Rather than create a method to clean up the mess, the DoD is looking to prevent it from being a problem altogether.

Indeed, the DoD is seeking a solution that would replace current training ground materials with biodegradable materials that would eliminate environmental hazards. Specifically, they want a solution based on bioengineered seeds that can be embedded into biodegradable composites. Such seeds wouldn’t begin to germinate until they’ve been in the ground for several months, the post notes.

In layman’s terms, the Army wants its spent bullets and casings to break down naturally and grow plants in the process. The DoD adds that animals should even be able to consume the plants without getting sick.

You can learn more about the job or submit a proposal over on the SBIR program website.