For the second time in a month, New Castle County Executive Paul Clark has replaced a longtime member of the Planning Board who has a history of objecting to development projects that had the support of county government.

Monday, Clark told Victor Singer, the board chairman for the last 13 years, that he would be replaced by Richard Killingsworth. Killingsworth is the deputy director at Nemours Health and Prevention Services.

Some residents and a county councilman think the change shows Clark is getting rid of his critics and stacking the Planning Board -- which makes recommendations to council about development projects and other land-use issues -- with pro-development members.

"The Clark administration and their allies are engaged in a concerted effort to crush respectful and intelligent dissent," Councilman Robert Weiner said. "It's a pattern to silence all critics who have knowledge and expertise on land-use issues."

Clark replaced 16-year Planning Board member Mark Weinberg last month. When Clark was County Council president, he was admonished by the county Ethics Commission after making a comment that Weinberg had "a prejudice" against retail jobs. Clark spoke during the meeting even though he had recused himself because the law firm his wife, Pam Scott, worked for represented the developer in question.

Scott resigned from the Saul Ewing firm in March to comply with a county Ethics Commission ruling that declared an untenable conflict of interest would exist unless Clark or Scott resigned.

Clark said Monday he's not getting revenge. Planning Board members  should have term limits, he said, adding that it's important to replace members every few years since they don't.

"It is my belief that these appointments should not be life terms and that other qualified people should be given the opportunity to serve," Clark said. "When you've been on these boards for several years, you wind up becoming the professional and not the citizen, and these are citizen boards."

Weinberg said last month he thought his opposition to Scott-represented developers played a role in his not being reappointed.

Singer said Monday he's had a longer run on the board than he expected. Unlike the other eight members, the chairman has no set length for his term.

"On one extreme, I find it objectionable," Singer said. "But the other extreme is to just say, 'Thank you,' so I thanked Mr. Clark when we talked."

Singer, 78, said he's getting tired of the job and is somewhat relieved to be off the board. He said any disagreements he had with Clark were inevitable.

"I don't think our disagreements had anything to do with this," Singer said.

Councilwoman Lisa Diller gave Killingsworth's name to County Executive Chris Coons a year ago. She envisioned him as a board member , not the chairman.

Killingsworth, 47, of Middletown, has worked across the country to promote healthy and sustainable communities through collaborative partnerships and responsible land-use planning, Clark said.

He's been the executive director of the Harvest Foundation in Virginia, which helped design active community environments and, as the national director of Active Living by Design, he promoted healthy lifestyles by designing communities differently.

"I nominated him because I think he will be a terrific addition to the board," Diller said.

Greenville resident Tom Dewson said Weinberg's departure is disturbing.

"First Mr. Weinberg, now this," Dewson said. "Two independent voices gone. This sets a new low for an administration beset with conflicts of interest. Something has to be done to preserve the integrity in county government."

Christine Whitehead of Mill Creek said she wasn't surprised by the move.

"Mr. Singer has years and years of knowledge and a brilliant mind," Whitehead said. "Pretty soon, there will be no one on the board that we can be positive will vote only in the public interest."

Weiner said he thinks longtime Planning Board member Sandra Anderson will be the next to go when her term expires in January. Anderson, Singer and Weinberg were considered independent voices.

"It's an absolute travesty that Vic was removed, and I'm literally devastated for the county," Anderson said. "I absolutely know I'm next."

Clark said he has not thought about Anderson's future.