After months of delays, the city will announce a final implosion date for the New Haven Memorial Coliseum before the end of the month, with preliminary preparations scheduled to begin as early as the end of this week, Deputy Director of Economic Development Tony Bialecki said Monday.

Originally set for last September, the implosion date has been repeatedly delayed by concerns that electric, cable and phone lines running under the New Haven landmark would be damaged during the implosion, Bialecki said. The original precautions to protect utility lines recommended by Stamford Wrecking — the company contracted to carry out the process — were considered inadequate by city officials, and a new team of engineers was hired by the contractor to reassess necessary procedures and ensure utility lines would not be damaged in the implosion, he said.

Bialecki said city officials and engineers are close to finalizing “nuts and bolts” of the new plan and will wait for all parties involved in the demolition process to sign off on the plan before naming a final implosion date.

“Everybody now is in agreement, but we all agree that we wouldn’t say it’s ready to go at a date until we have a joint announcement,” Bialecki said. “We don’t want any more false starts.”

The implosion of the New Haven Coliseum is the first concrete step in the $230 million plan to bring Gateway Community College downtown. The Gateway Project, which city officials hope will help jumpstart a revitalization of the area surrounding Church and Crown streets, will also incorporate Long Wharf Theater, the Knights of Columbus and retail-residential development into downtown New Haven.

Although it has been months since the Coliseum was originally expected to be demolished, Ward 7 Alderwoman Bitsy Clark said that business owners and residents in her ward, which includes Ninth Square — a downtown district directly adjacent to the Coliseum — have been thankful for the delays, as they represent the city’s efforts to ensure that the implosion will not negatively affect the local area.

“Since 9/11, people have been a little leery of implosions, so when they announced a year ago people got all upset,” said Clark, who sits on the city’s development commission. “[Now, the city] wants to be absolutely sure that nothing goes wrong here. The people in the Ninth Square are just as happy to have this delay, so they’re feeling like this is a good thing.”

Michael Morand, Yale’s associate vice president for New Haven and state affairs, who also sits on the city’s development commission, said delays and changes in a project of such scope are to be expected.

“The Coliseum demolition has been proceeding with appropriate caution to satisfy the concerns of the utilities and adjacent property owners,” Morand said. “The extended process does not have any major negative impact on the overall redevelopment plans.”

Clark said the last major implosion carried out in New Haven — the Century Building at the corner of Church and Grove streets in the late 1980s — sent “astounding” amounts of dust into the air, and local residents are worried the same will happen with the Coliseum’s implosion.

To minimize environmental impact, city officials decided to dismantle a large part of the Coliseum starting last October with the help of a 175-ton excavator. By January, only the skeletal superstructure of the Coliseum and the parking deck that sits on top of it remained intact.

Clark said that although addressing environmental concerns is crucial, she believes the city needs to move forward as quickly as possible to finish the implosion process.

“It’s not to anybody’s benefit to keep this thing half up and half down,” Clark said. “It would be to everyone’s benefit to get this thing down as fast as possible, even if nothing replaces it except a parking lot.”

Officials had been planning to place a hotel and conference center, new office buildings for the Knights of Columbus, a new facility for the Long Wharf Theater and apartment buildings on the Coliseum site, but a feasibility study for the site released in February determined that the location would not be ideal for a full-service luxury hotel.

Morand said that although there is a need for more luxury hotel rooms downtown, the Coliseum site was not ideal for that purpose and could be better utilized.

“The development of that site should be market-driven and not determined by fiat,” Morand said. “It is one of the few sites where a tall building might go, and its economic potential should be maximized to the fullest.”

Ideas about what to put on the site circulating among residents and city officials have included park land, a supermarket, or an indoor market modeled after the one in New York City’s Grand Central Station, Clark said.

The Gateway Project was initially proposed by Mayor John DeStefano Jr. two years ago and was approved by the Board of Aldermen last February.

Construction on Gateway Community College is expected to begin in 2008.