Investigations into the illegal dumping of concrete and other debris into Mailiili Stream are continuing while the city awaits approval from various state and federal agencies to begin the cleanup, officials say.

The city has submitted its plan for removal of debris and restoration of the stream bed and is awaiting approval from the U.S. Environmental Protection Agency, said Jeoffrey Cudiamat, city director of facilities maintenance.

Cudiamat provided an update on cleanup efforts yesterday to the City Council's Public Safety and Services Committee.

He said the plan was submitted about two weeks ago and a response is expected within six to eight weeks of that submission.

Cudiamat added that his department has taken steps to ensure that a similar dumping does not happen again. Those steps include new training for managers and a review of standard operating procedures.

He said he could not discuss specifics about the cleanup and what led to the dumping because of investigations that are still being conducted by the EPA and state Department of Health.

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

Cudiamat previously said the site was not being used as a dumping ground and that the concrete was being used to create a temporary path to provide maintenance to remove debris.

Mailiili Stream, along the Waianae Coast, is frequented by endangered Hawaiian stilts. The watchdog group EnviroWatch Inc. first reported the activity in the stream to the city in June. A month later the EPA ordered the city to clean up the stream and restore the stream bed.