AUGUSTA – A controversial bill that allows municipalities to require developers of new retail stores of 75,000 square feet or more to pay up to $40,000 for an impact study was signed into law Wednesday by Gov. John Baldacci.

The Informed Growth Act, LD 1810, faced opposition by the Maine State Chamber of Commerce and other business groups, but the bill’s sponsor, Rep. Chris Barstow, D-Gorham, said the law was embraced by many small-business owners.

Barstow’s goal with the bill was “to try to find a way to get information to communities,” he said Wednesday.

The law will help municipalities strike a balance between preserving the quality of place that most value in their downtowns and encouraging economic development, he said.

Barstow’s wife’s family lives in the Waldoboro and Warren area, he said, where debate has raged in recent years over so-called big-box retail development.

“I’ve had firsthand knowledge of this issue,” he said.

With rhetoric on both sides of the debate reaching extreme tones, he concluded municipalities needed a tool to “distinguish between myth and fact.”

Under the new law, a retail business proposing to build a new store of 75,000 square feet or more of gross floor space, whether in multiple buildings or on multiple floors, could be asked to deposit $40,000 with the municipality.

The funds would be used “to pay for a comprehensive impact study, a public hearing and related municipal staff support in order to estimate the positive and negative economic and environmental effects of the project on the local area prior to permit approval,” according to the bill’s text.

The study will take into consideration nearby municipalities if they are expected to be affected.

A list of qualified consultants able to complete the studies will be included on the State Planning Office Web site, Barstow said.

The law ensures that municipalities without site plan or zoning ordinances have the ability to assess projected impacts of large-scale retail development without having to pay for the study.

“Most of these projects are in the millions of dollars,” Barstow said, so the impact study cost equates to “pennies on the dollar” for the developers.

Though large business lobbying groups such as the state Chamber opposed the bill, Barstow said 175 small-business owners either wrote about their support of the proposal or spoke in favor of it at the hearing. The bill was reviewed by the Legislature’s State and Local Government Committee, of which Barstow is the House chairman.

Barstow believes many cities and towns are unaware they have the power to order such a study, or are reluctant to do so, and so operate in the dark about the impact new big-box retail stores will have. Municipalities that already require impact studies of such retail applicants are exempt from the law.

“I think some communities are unaware of the information they need,” Barstow said.

Big-box developments can affect municipal services such as police, fire, sewer and water; snarl traffic; and spur related but smaller retail growth that can hurt the economic viability of downtowns, Barstow said.

But the studies will approach retail proposals without bias for or against, and instead separate perception from reality so communities can have a clear understanding of what changes, if any, a new store will bring, he said.

Barstow believes the study will not stall retail projects.

“We think it’s something that would integrate into the normal [review] timeline,” he said.

Among the bill’s co-sponsors were Sen. Elizabeth Schneider, D-Orono; Sen. Dennis Damon, D-Trenton; Sen. Dana Dow, R-Waldoboro; Rep. Ted Koffman, D-Bar Harbor; and Rep. Jonathan McKane, R-Newcastle.