Calvert County officials are continuing their consideration of new regulations that would specifically limit the size of future big-box retail stores -- regulations that could have an immediate impact on a proposed expansion of the Wal-Mart in Prince Frederick.

Last week, the county commissioners scheduled a July 13 public hearing, to be conducted with the Planning Commission, on the proposed big-box regulations, which have been in the drafting process for more than a year.

The version of the proposal to be considered at the hearing does not contain a specific cap on the square footage or size of the large stores. However, it does include a range of size limits that the commissioners may choose from if they decide to enact the regulations.

A majority of the commissioners indicated their support Tuesday for a proposed requirement that the big-box stores be limited to 150,000 square feet, though the proposal also gives the board the option of reducing the maximum size even further, at any increment down to 75,000 square feet.

The Prince Frederick Wal-Mart on Route 2/4 contains 91,424 square feet. But the retailer is seeking permission from the Planning Commission to build a 109,598-square-foot addition. If the commissioners proceed with the proposed big-box regulations, the expansion would have to be, at the very least, scaled back.

"It depends on what passed," Frank A. Jaklitsch, director of the county's Planning and Zoning Department, said. "It may kill it."

The move to limit the size of the big retail stores has primarily stemmed from a concern about additional traffic the stores would probably generate on already congested roads. Some of the county commissioners remain so concerned about the scope of such retail stores that they objected to the range of size limits to be considered at the public hearing.

Commissioner Gerald W. Clark (R-Lusby) said he thought a 150,000-square-foot store is "too big" for Calvert. "I think we need the roads and infrastructure to support that," Clark said.

Tuesday's vote to present the regulations at a public hearing came a little more than a year after the commissioners asked the Planning Commission to expedite the drafting of regulations to specifically govern the size, design and location of big-box stores. At the time, the county commissioners said they wanted planners to "green light" work on the rules in part because there were a number of pending proposals for commercial developments that would fall under the big-box definitions.

The Planning Commission has recommended that big-box stores be restricted to parts of Dunkirk, Prince Frederick, Lusby and Solomons. But despite that recommendation, drafting the overall regulations has turned out to be a painstaking process.

Notwithstanding the slower-than-anticipated progress on the new regulations, the commissioners decided in November that whatever provisions are adopted, they will apply to all proposals for such stores that are awaiting final approval from planning officials. Proposed projects that could be subject to the new rules can be found from one end of the county to the other. They include the Lusby Commons development in southern Calvert, the Wal-Mart expansion in Prince Frederick and a proposed Wal-Mart in Dunkirk at the north end of the county.

Those developments could also be affected by provisions of the proposed big-box regulations that would govern how other stores could be connected or built next to the large retail outlets.

The commissioners have been pursuing an agreement recently with the developer of the Dunkirk Wal-Mart, allowing the roughly 144,000-square-foot store to be exempt from the big-box regulations if the builder made road improvements in the area, Jaklitsch said. That Wal-Mart is part of a larger commercial development.

But the Planning Commission would have to sign off on such an agreement and make a determination that it is consistent with the county's comprehensive and master plans, Jaklitsch said.

Another issue to be decided is whether developers of the big-box stores should have to pay an excise tax. The fee presumably would help the county bear the costs of road improvements needed to accommodate additional traffic generated by the commercial centers.