THE HAGUE, Netherlands (AP) — A Dutch inventor says that after a series of setbacks his system for catching plastic floating in the Pacific between California and Hawaii is now working.

Boyan Slat, a university dropout who founded The Ocean Cleanup nonprofit, announced Wednesday that the floating boom is skimming up waste ranging in size from a discarded net and a car wheel complete with tire to chips of plastic measuring just 1 millimeter.

Slat says the results are promising enough to begin designing a second system to the Great Pacific Garbage Patch, an area of floating plastic trash twice the size of Texas.

But he sounded a note of caution, saying “if the journey to this point taught us anything it is that it's definitely not going to be easy.”