The door is "slightly ajar" to memorial proposals not located within the World Trade Center's proposed memorial site 30 feet below street level, Lower Manhattan Development Corp. chairman John Whitehead said yesterday, suggesting that a design at street level could be selected.

After yesterday's LMDC board meeting, he backtracked in a statement, saying the agency is committed to preserving architect Daniel Libeskind's vision, "a hallmark of which is the recessed memorial setting, and the winning memorial design must be consistent with that vision."

But Whitehead may have gotten it right the first time. The agency's project plan for the World Trade Center site is about to go through a rigorous environmental review process, and by law, the public gets its say.

The agency's interim president, Kevin Rampe, confirmed Libeskind's site plan could change "in response to environmental concerns."

New York City environmental reviews have derailed many a project, with advocacy groups often suing to change or halt projects.

"People try to trip you up during an EIS [environmental impact statement] review," said one person familiar with the review process, who didn't want to be named. "If someone sues to stop it [the project], you have to show the EIS addressed the concerns they brought up. If the EIS looks flawed in some way, you can have it thrown out."

Several lower Manhattan residents, who have already testified at public hearings, can be expected to testify to raise the memorial site to ground level.

The agency will hold an initial public hearing to define the environmental impact statement's scope on July 23.

The agency plans to complete the review in April 2004, with construction to begin on the 1,776-foot-high Freedom Tower in August 2004 - or sooner if possible.

The LMDC also is facing pressure from government officials and advocacy groups to distribute the remaining $1.3 billion allocated by Congress for downtown's redevelopment.

A dozen affordable housing advocates attended yesterday's LMDC board meeting, standing silent with signs asking that the agency fund low-income housing downtown at yesterday's LMDC meeting.

"We were here to urge the LMDC to provide funds so that housing that's built in lower Manhattan is mixed income housing that's affordable to a wide range of incomes for the downtown community," said Stephanie Greenwood, a member of the Liberty Bond Housing Coalition, her sign calling for "housing for a diverse downtown."

City officials already made a $200-million request to fund Mayor Michael Bloomberg's $3-billion program to build or fix up 65,000 affordable housing units over the next five years.

"I don't think necessarily there is any disagreement that it is a major priority," said Deputy Mayor Daniel Doctoroff, speaking after yesterday's meeting. "I'm hopeful that we'll start seeing some step on that pretty soon ... [LMDC] money will be set aside for some affordable housing."

Officials at the LMDC, which was created by Gov. George Pataki to oversee downtown's redevelopment, have not yet made a decision about the city's request.

But the agency announced a series of community workshops downtown this summer to collect any ideas about how to spend the $1.3 billion from downtown's residents.