Sarah Harmer sits at the centre of the head table. To her left is Burlington Mayor Cam Jackson, a man who spent 22 years at Queen's Park, learning his way around the corridors of power. To her right is world-renowned architect Douglas J. Cardinal, the man who designed, among other things, the $340-million Canadian Museum of Civilization in Hull, Que.

It's an uncomfortable place for Harmer, possessor of one of the sweetest voices in Canadian pop music. The double Juno winner is used to taking the stage at sold-out theatres. But here, in a meeting room at the Burlington Art Centre, the 50 or so people in attendance, including three city councillors, are waiting to hear her speak, not sing.

Harmer has increasingly found herself in this situation since she cofounded PERL (Protecting Escarpment Rural Land) to oppose a quarry application on Mount Nemo in north Burlington. It's an issue close to her heart. She was raised on a farm not far from the site. Her parents, Isabelle and Alan, still live there. During the past couple of years, Harmer figures she has spent more time battling the quarry than on her music.

The fight has kept her on a rigid schedule. Take Thursday. She left her current home near Kingston at 5:45 a.m. to attend an environmental meeting in Toronto where Premier Dalton McGuinty was speaking. She had a brief chat with the premier about the quarry.

"He was aware of it," Harmer told The Spectator. "I think he understands the competing interests and about where the best natural remaining areas are."

From Toronto, she drove to Burlington where she hopped on a helicopter at 1:45 p.m., with Jackson and Cardinal, to tour the escarpment lands in question. Then, down to earth for a quick bite before heading to the Burlington Art Centre for a Spectator photo shoot and the 7 p.m. public meeting.

The 37-year-old singer only had a few minutes to prepare notes for her speech. Harmer doesn't need to refer to them. She speaks eloquently about the lands, referring to the Neutral Indians who once inhabited the area and a centuries-old longhouse recently discovered at nearby Lake Medad. Instead of pointing accusatory fingers at the quarry diggers, she speaks of the potential future for the area as a natural reserve. Maybe an outdoor ampitheatre, maybe trails, vineyards, galleries. The key is community discussion and vision.

Yesterday, Harmer took a day for music, rehearsing with fellow Juno-winning artists Feist, Bruce Cockburn and Derek Miller for a benefit concert to be held this afternoon on a farm atop Mount Nemo. As many as 750 people are expected. (For information, visit perlofburlington.org or sarahharmer.com). At $99 a ticket, the concert will raise tens of thousands of dollars for PERL to commission scientific studies, specifically on the local water table. Harmer says she's read "hundreds and hundreds of pages" of reports.

"She's the catalyst that we're all nucleating around," Jackson, a quarry opponent, says. "She's walking the walk and talking the talk. You don't hear from Sarah until she does her homework."

Harmer is a seasoned performer. She's been singing all her life, even performing with a local barbershop quartet as a child. She admits to stage fright, however, at the lectern.

"I had to screw up the courage for that," she says after the three-hour meeting. "It's really different than going with my music and putting on a show. It's more of an unknown."

Cardinal is the star of the show Thursday night. He mesmerizes the meeting with a slide show of the many "organic" projects he's done, and how they have fit in naturally with the environment. He talks a lot about native spirituality and "interconnectedness."

He's aware of the need for aggregate (crushed stone for roads and concrete). Many of his buildings are heavy with concrete. But it is "insanity," Cardinal says, to take the gravel from such an environmentally sensitive area, a jewel of the Niagara Escarpment, a UNESCO World Biosphere Reserve.

Cardinal points to a red circle on a map. It's the quarry. "This area in the centre is disturbing the whole natural area. Somehow it has to be healed."

Cardinal's son, Brett, is there. He, too, is an architect and part of the firm. His doctoral thesis, interestingly enough, focused on the possibilities of turning an abandoned quarry into a musical ampitheatre. Brett enjoys playing drums and likes to talk about "the healing power of music."

Nelson Aggregate Co. has been operating a quarry on Mount Nemo for more than 50 years. It's one of more than 40 on the Escarpment, and employs 45 people. The pit will be dug out in five years, and the company has asked the provincial government for permission to dig an adjoining 82 hectares, more than double the current area. The company contends the new quarry is necessary to meet Halton's growing demands. To bring gravel from farther away forces heavy trucks to drive greater distances, increasing costs and creating more pollution. It disputes PERL's claims that the new quarry would strain the area's water resources.

Nelson president Norm Elmhirst attended the meeting.

"I was disappointed in the lack of specific proposals for the remediation of the quarry," he said, noting Nelson's remediation plan includes the eventual creation of two lakes.

Nelson first proposed the new quarry four years ago. The application is now before the Ontario Municipal Board, with a hearing expected next year.

So far, Harmer has managed to balance the environment with the music. She's the latest in a long line of politically active musicians, stretching back to Pete Seeger, Woody Guthrie and Paul Robeson. She cites artists such as Cockburn, a longtime environmental and peace activist, and English protest singer Billy Bragg as mentors.

Two years ago, Harmer released the acclaimed I Am A Mountain, which included the song Escarpment Blues. She followed with a musical tour of the Bruce Trail. A Juno-winning DVD was made from the tour.

It's been two years since I Am A Mountain, and she admits the followup is coming slow. But it is coming.

"Right now I'm collecting material. I don't feel obligated in any direction other than my heart. And right now songs are coming out of this experience."

grockingham@thespec.com

905-526-3331