KIHEI, Maui — Cracks in plastic lumber made from recycled milk jugs have stalled a $2.2 million federal project to build an elevated boardwalk at the Kealia Pond Natural Wildlife Refuge.

The project includes a nearly half-mile-long boardwalk with three kiosks, a bridge over a pond outlet, interpretive panels and a small parking lot. Test piles were driven into the coastal mudflats in December 2003, and construction began in earnest in October 2004, after a delay to accommodate the nesting season.

The boardwalk was to have taken four months to complete, but during the final inspection in January, cracks were found in decking and handrails manufactured by Aloha Plastic Recycling of Kahului.

Federal officials said they don't know when work on the 2,200-foot boardwalk will resume or how much additional money will be needed to replace the damaged materials.

Kealia refuge manager Glynnis Nakai said she's hoping the boardwalk will open next summer.

In the meantime, birdwatchers will have to endure another peak season for migratory birds without the benefit of an enhanced viewing platform.

Ignoring signs that the boardwalk was closed, David and Patty Berg of Tacoma, Wash., detoured from their beach walk earlier this week to take a stroll on the structure, spotting a trio of Hawaiian stilts, or ae'o, wading in a small pool.

The Bergs said they were impressed.

"It's wonderful to have this, and it's nice to have areas where you can sit," Patty Berg said.

AMONG LAST OF WETLAND

The 700-acre Kealia Pond National Wildlife Refuge on Maui's south shore was established in 1992, and includes some of the last remaining natural wetland habitat in Hawai'i. Delicate ae'o and more sturdy native coots, 'alae ke'oke'o, live there year-round, and migratory ducks and shorebirds visit in the fall, winter and spring. Kealia Beach, next to the boardwalk, is a nesting ground for the endangered hawksbill turtle.

Busy North Kihei Road slices through the refuge, with rare birds nesting within a stone's throw of passing cars.

The Federal Highway Administration provided most of the funding for the project under a roadway enhancement program. The agency is working with Central Construction Inc. of Kahului to replace the plastic lumber, perhaps under a cost-sharing arrangement, said FHA project manager Dave Gedeon in Denver. He said wood or a wood composite product will be used.

Gedeon said the Maui-made plastic lumber suffered from "quality-control defects." He said a lot of effort was put into using environmentally friendly products, "but unfortunately the material didn't perform up to expectations."

He said he would hate to see anyone shy away from using material made from recycled plastic, but that perhaps the boardwalk wasn't the best use for it.

NAILS USED, NOT SCREWS

Plastic lumber is commonly used in boardwalks on the Mainland, and Tom Reed of Aloha Plastic Recycling said the problem was with construction specifications that called for using deck nails rather than screws to secure the planks. Reed said the impact of driving the nails into pre-drilled holes damaged the decking material.

Reed said Aloha Plastic Recycling products have been used successfully for years, including in making benches and picnic tables purchased by the City & County of Honolulu.

Stanley Matsumoto of Central Construction said specifications called for nails, although other plastic-lumber projects he is familiar with specified using screws. He indicated screws might have been a better choice at Kealia, but said there also were problems with the decking material, which had a "reaction" to the hot climate and cracked.

An informal inspection of the boardwalk this week showed numerous small cracks, most occurring at the nail sites. In some spots, the nails were slightly protruding from their holes.

Maui County recycling coordinator Hana Steel heartily recommends plastic lumber, when installed properly.

"Of course it's going to crack if you nail the stuff," Steel said. "Anyone who manufactures plastic lumber knows that you have to use screws."

Steel said she hopes someone will be able to reuse the plastic lumber that will be removed from the boardwalk, and that it won't end up in the landfill.

LACK OF RAW MATERIAL

Before construction of the Kealia boardwalk began, a public campaign featuring "Maika the Milk Jug" encouraged Maui schoolchildren and others to collect 1.5 million plastic gallon jugs to be used as raw material for the project.

Reed said not nearly enough jugs were collected, and that he had to import from the Mainland 90 percent of the recycled plastic used for the boardwalk. He said that the lack of a guaranteed source of raw material forced him to close Aloha Plastic Recycling last month.

He said there's no chance of resuming operations until Maui implements curbside recycling. County officials said that's a goal, but it won't happen anytime soon.

Reed said his glass recycling and container redemption operations are doing well.

STILL GREAT FOR VIEWING

Refuge manager Nakai said that even without the boardwalk, there are plenty of opportunities for the public to observe native and migratory birds at Kealia. One of the best viewing areas is near the refuge office, whose entrance is off Mokulele Highway.

In addition to the hundreds of stilts, coots, plovers, herons, sanderlings and other birds feeding at the pond this week was an American avocet, which made its first known appearance in Hawai'i in September at Kealia. It has a long, upturned bill and is similar to a Hawaiian stilt, but larger.

Reach Christie Wilson at cwilson@honoluluadvertiser.com.