Complex sentence: Most of the wastes from Owerri are dumped at the Avu landfill in Owerri West on the Port Harcourt highway, which creates a high concentration of phosphate and nitrate in the Otamiri.
Split into simpler sentences: Most of the wastes from Owerri are dumped at the Avu landfill in Owerri West on the Port Harcourt highway. The Avu landfill creates a high concentration of phosphate and nitrate in the Otamiri.