Honolulu nature lovers did something for Mother Earth yesterday, dropping off more than 10,000 old shoes at Honolulu Hale to be recycled into play and sports surfaces as part of Earth Month.

Organizers said residents donated 10,132 shoes yesterday at Honolulu Hale. A collection will also be held next month on Kaua'i.

People drove up to the curb and dropped off boxes and bags of tennis, basketball, hiking, walking and running shoes that had all seen better days.

Volunteers heaped the shoes onto a growing pile in front of City Hall.

Honolulu fire trucks also arrived in full regalia to drop off shoes collected at fire stations.

"We're very pleased to be doing this again," said Mayor Mufi Hannemann, who was head cheerleader for the effort. "It has a double benefit. It reduces the amount of material going to the landfill and provides material for recycling."

Since 2006, the city had partnered with Niketown in Waikīkī in the Nike Reuse-A-Shoe program. Niketown has closed, and this year the Hawai'i Nature Center volunteered to become the major sponsor of the event.

The program has been renamed Recycle-A-Shoe.

Here's how the recycling works: The shoes are disassembled and the bottom of the shoe, known as the outsole, is ground up into rubberized pellets to be used in playgrounds and running tracks.

The midsole, the next level up from the outsole, is turned into grind foam used in the construction of tennis courts and weight rooms.

Which leaves the uppers, which can be converted into layers of fabric padding used beneath the wooden floors of basketball courts.

The Hawai'i Nature Center is a nonprofit organization dedicated to educating the state's children about Hawai'i's unique environment. It says that more than 80,000 people have taken part in the organization's environmental educational programs since it started in 1981.

The collection on Kaua'i will be held from 10 a.m. to 6 p.m. Saturday and Sunday at Vidinha Stadium.