Some Hawaii Island residents are disturbed by the amount of trash left behind after the Ironman World Championship in Kona over the weekend. Event organizers say clean up could take a week. 

The Ironman is one of the most physically challenging races for athletes and organizers. Competitors tackle a course that's more than 140 miles, that's 2.4 miles of swimming, then onto 112 miles of biking and running a marathon along the Kailua-Kona coast. Volunteers and staff clean up during and after the race. 

"For the bike course, we had three different groups that were doing cleaning up to cover the distance from Kailua Town to Hawi and back,” Sheryl Cobb, Ironman Aid Station director, said. 

One resident says she saw spectators littering despite sitting right next to trash cans.

"It was crazy. I wouldn't go to your city, why would you come here and do that? It was just a massive amount of garbage,” Stacia Miller, a Kona resident, said. "My friend and I walked up and down the pier and we just kept picking up trash until our hands were full." 

On Monday morning, another resident also collected dozens of zip ties on Kamakahonu Beach. Ironman says it's committed to keep Hawaii clean.

"We're part of this community. We live here, we don't want the race to have a negative effect on anything so we're out there trying to clean up everything we can,” Cobb said. 

Environmental groups like Sustainable Coastlines Hawaii believe the plastic situation overall continues to get worse. 

“Every time we have an event where we use things like single use plastics, inevitably there's gonna be something that gets into the ocean or we don't have a way to dispose it properly at the end,” Rafael Bergstrom, Sustainable Coastlines Hawaii, said. 

They hope other big events will add sustainable features like water stations instead of giving out bottled water to lower the amount of trash.

"I think there's more awareness that is growing, our education efforts are starting to really work but we have to continue to get better,” Bergstrom said. 

The Ironman aid station director says that would be challenging because bikers can't stop during the race. 

Another initiative from Ironman giving back to the environment: recycling. It says plastic bottles, cans, cardboard boxes and other materials are all sorted and broken down after the race for recycling.