City officials yesterday submitted to the Environmental Protection Agency a detailed description of the March 24 rupture of a sewer line in Waikiki and the 48 million gallon discharge of raw sewage into the Ala Wai Canal that followed.

City spokesman Bill Brennan said Environmental Services Director Eric Takamura sent the report to the EPA's Region 9 office in San Francisco late yesterday afternoon. The city declined to release the information to the public until officials receive confirmation that the federal office received the report, Brennan said.

EPA officials could not be reached to comment yesterday because the California office had closed by the time the city sent the report.

When the Beachwalk main broke on Kai'olu Street during heavy rains, Mayor Mufi Hannemann said the city was forced to release tens of millions of gallons of raw sewage into the canal rather than risk the sewage backing up into buildings.

The raw sewage fouled nearby waters and closed some of Waikiki's most famous beaches, creating huge public health and environmental concerns.

And EPA officials have expressed concern about the size of the spill, noting that the request for a report is the first step toward enforcement action.

Reach Robbie Dingeman at rdingeman@honoluluadvertiser.com.