Roger and Colleen Mehrer surveyed the muddy water at Ko Olina and watched as workers hauled away plastic bags of trash that had made its way from Waimanalo Gulch Sanitary Landfill above Farrington Highway.

The part-time Ko Olina residents did not see what was inside the bags, but they had read in yesterday’s Star-Advertiser about the medical waste that had washed ashore at the West Oahu resort’s lagoons and elsewhere along the Leeward Coast.

"How can medical supplies wash from the dump all the way down here?" Roger Mehrer said. "That’s what surprised me."

Gary Gill, state deputy health director for environmental health, said, "Obviously, this situation should never have happened."

Rain accumulating at a reservoir above Oahu’s only municipal landfill poured into a "cell" of waste, causing it to overflow and send a torrent of debris-laden storm water down a concrete spillway and into waters just off the Ko Olina Resort on Wednesday, said officials with the city and Waste Management Inc., the company that operates the landfill.

Medical waste, including syringes and vials that appeared to contain blood, were among the debris that washed ashore along beaches at Ko Olina’s four lagoons and other western shores, including the area around Kalaeloa Harbor.

Gill said his agency was still compiling data on the waste that washed ashore and testing water quality samples from different points along the coast to determine whether there was contamination. Meanwhile, Ko Olina’s lagoons as well as beaches elsewhere along the Leeward Coast remained closed to the public until further notice.

"The landfill is supposed to be designed to divert any floodwaters from the mauka areas, push those waters along the side of the landfill," Gill said. "The waters should not have crossed on top of the landfill; they should not have eroded a cell full of waste that was placed in that landfill; and certainly no waste, medical or otherwise, is supposed to leave this landfill."

Joe Whelan, Waste Management’s general manager for the landfill, said the company was weeks away from completing a bypass route that would have diverted the storm water from the upper reservoir straight into the drainage way, avoiding the landfill cells.

The additional measures were required under Waste Management’s latest permit allowed by the state Land Use Commission. Granted in September 2009 after much debate and controversy, the permit allows the landfill to expand and continue operating, but only through 2012.

Had the improvements been completed, the water still would have ended up in the filtration basin at the base of the landfill, but it would not have gone through the landfill cells, picking up rubbish along the way, Whelan said.

Five inches of rain fell on Dec. 19, and then again about a week later, so water had already begun to accumulate along the route and in the basin below, Whelan said. The 11-inch rainfall that occurred late Wednesday and early Thursday caused the water to go over the top, he said.

Tim Steinberger, city director of environmental services, said the storm was a "catastrophic weather event" and that the overflow was caused by an extraordinary set of circumstances. "We haven’t had a rain like this, ever."

Asked whether it was time for the city to reassess its design standards, Steinberger said, "That’s a discussion I think perhaps the engineers should have."

Nonetheless, Steinberger said, "As far as what ended up at the beach, obviously, we’re very concerned. We’re very concerned about any issue that affects the public health."

The landfill is allowed to accept medical waste, but it is supposed to be sanitized, Gill said.

It is too early to say whether Waste Management or the city will be fined by either the Health Department or the federal Environmental Protection Agency, he said.

Crews hired by Waste Management cleaned the debris from the mouth of the drain and nearby beaches through much of the day.

Below Farrington Highway, officials and residents at Ko Olina Resort were unhappy with the situation.

Ko Olina Community Association General Manager Ken Williams said various types of trash accompanied the storm water coming out of the drain Thursday. "It was covered," Williams said.

The waste washed ashore on all of Ko Olina’s beaches, he said. "There was a mixture of waste … a mixture of trash that would come out of the landfill."

Ko Olina Resort has long opposed the landfill’s expansion, and Williams reiterated the call for its shutdown yesterday.

"This thing was supposed to close in 1998, and it’s had extension after extension," he said. "This is probably the worst occurrence that we could imagine, with the most direct impact we could have at our resort."

The beaches at Ko Olina and elsewhere along the Leeward Coast are expected to remain closed to the public until water monitoring results show the water is safe.

Mehrer, the part-time Ko Olina resident, said he is concerned about what the waste is doing to the ocean environment in the area, which is usually teeming with fish and turtles. "What is it doing to the environment and ecosystem that we can’t see? And how long will it take to clean up?"

Because of the landfill’s problems, the facility will remain shut down until at least next Saturday, Steinberger said.

Most of the city’s municipal solid waste now goes to HPOWER, the city’s waste-to-energy facility in nearby Kalaeloa, where it is burned to make fuel. The majority of what goes into the landfill, therefore, is composed of bulky items that cannot be burned.

The city is limiting its bulky item pickup service to metal items, such as washing machines.

 CORRECTION: Drainage pipes carried storm water from the Waimanalo Gulch Sanitary Landfill under Farrington Highway and the Ko Olina Resort, emptying at an ocean outfall. A graphic in a previous version of this story stated that the storm water was carried under the highway and onto Ko Olina property.