The city has been ordered to remove concrete and other debris that a federal agency says was illegally dumped in Mailiili Stream, a Leeward Coast area frequented by endangered Hawaiian stilts.

In a ruling issued yesterday by the U.S. Environmental Protection Agency, the city must stop any further disposing of materials into the stream and, within 60 days, come up with a plan to remove the materials and restore the stream. The city also is charged with properly disposing of the debris and installing erosion and sedimentation control measures.

“;This order will protect the coastline and water quality by removing the unauthorized fill and restoring the Mailiili Stream to its previous condition,”; Alexis Strauss, the EPA's Water Division director for the Pacific Southwest region, said in a news release.

Jeoffrey Cudiamat, director of facilities maintenance, said crews already had begun work to remove some of the debris since it was brought to the city's attention in June, but had been advised to await further guidance.

“;As we have stated previously, it appears that city workers were using the concrete material to restore an access path along the stream bank in order to facilitate flood control maintenance work there, but had not obtained necessary permits first,”; Cudiamat said in a written statement. “;We are working to ensure full compliance with such requirements in the future, and have already taken affirmative steps to complete the action items set forth in the EPA's order.”;

  Concrete rubble from sidewalk repairs reportedly was placed in the stream area to restore an access road along the bank that was used to cut brush. The Health Department said no permit was issued for the dumping.

Concerns were first raised by the watchdog group EnviroWatch Inc.

The EPA says the city should consult with the U.S. Army Corps of Engineers to obtain the needed permits for the cleanup.

Laurence Lau, deputy health director for environmental health administration, said the state agency's investigation into the activity is continuing and “;will be finished very soon.”;

“;It's a serious matter, and they are treating it that way,”; Lau said of the EPA decision. He said he could not discuss the investigation and whether the state might require additional action or add other penalties.