The Suffolk County Planning Commission voted 7-0 yesterday to reject construction of a Wal-Mart store along Riverhead's booming Route 58, but the vote will have no impact because the board fell one short of a quorum.

A resolution to follow the planning staff's recommendation came up short when board member Donald Fiore, a member of IBEW Local 25, abstained because his union had interest in the project, which would be one of the largest on the retail strip.

Had a planning commission resolution passed, the Riverhead town board would have needed a majority plus one -- or four of the five town board members -- to OK the site plan on the 194,000-square-foot proposal. Now a simple majority is needed.

The unusual commission vote comes at a time when there are five vacancies on its 15-member board, making it difficult to achieve a quorum and at times rendering it powerless to take action. The vacancies arose after County Executive Steve Levy's legislation early this year set standards for commission membership and barred party and appointed government officials as well as members of local zoning boards.

Levy acknowledged there's been a "transition period" but discounted the impact of the vacancies. "I think the message has been sent," he said. "These big box stores will lead to traffic gridlock."

Town Supervisor Phil Cardinale said the town board's job in reviewing the site plan is "mostly ministerial" in trying to reduce the environmental impact, conditions that should be hammered out within several weeks.