Friends of Frederick County released a statement last week calling for the county to adopt new development regulations with environmentally friendly practices. The nonprofit group has a mission to promote quality of life, sustainable land use and watershed protection.

Earlier this month, the county's planning commission approved a revised site plan for the 515,026-square-foot warehouse and distribution center at the Intercoastal Industrial Center on Baldwin Road in Monrovia.

Friends members objected to the plan, which does not adequately protect Bush Creek and downstream waters, according to the statement.

The most recent version of the plan calls for 26 acres of asphalt and 16 acres of concrete. That could be a problem because asphalt absorbs heat and could transfer that energy to neighboring waterways.

Concrete is lighter in color than asphalt and reflects heat back into the atmosphere.

C. Robert Dalrymple, an attorney for the Costco project, was unavailable for comment Wednesday.

The county now has no regulations to prevent overheating of runoff water.

County Commissioner Kai Hagen said he would support looking at the issue during the county's review of its land use regulations.

"By taking a few relatively simple measures, we can significantly reduce the local effect," he wrote in an e-mail. "Planting trees, using white-colored roofing and using lighter-colored pavement are three examples of things that can make a difference."

He also serves on the planning commission, but abstained on the Costco vote.

Catherine Forrence, the only planning commission member to vote against the site plan, said she was uncomfortable with the potential for heat sink, the natural heat transfer that takes place between parking lots and the surrounding environment.

She's disappointed Costco pulled back from an earlier agreement with the planning commission in which it would have used 42 acres of concrete rather than the 26 acres of asphalt now being discussed.

The Costco project was supported by economic development programs in Frederick County because it would create roughly 300 jobs with an average salary of $45,000 a year.

It was fast-tracked, which restricted the window of time for planning staff to review the proposal.

Anne Merwin, the policy information director at the Potomac Conservancy, said in the Friends statement that environmental groups worry about plans, such as Costco's that use large amounts of pavement.

"Parking lots the size of several football fields might be good for business, but they are bad for the environment," Merwin said. "Surfaces that prevent water and pollutants from soaking into the ground allow more bacteria and sediment to collect and wash back into streams and ultimately choke nearby water sources and the Chesapeake Bay with pollution."

Friends of Frederick County wants the commissioners to consider voluntary low-impact development techniques such as preserving vegetation and soils and using rain gardens, porous pavement and green roofs to capture, treat and slow the release of storm water.

Communities in Virginia have used voluntary techniques while awaiting statewide standards.

"We know the Chesapeake Bay is degrading and not improving, and it is our responsibility as people who reside in Frederick County to take care of it, to take care of those streams," said Janice Wiles, executive director of Friends of Frederick County. "Whether it's mandated by law or not, it's the right thing to do."