Critics of a controversial power line are calling on the province to take a close look at the environmental impact of the project.

The group, Responsible Electricity Transmission for Albertans, has sent a letter to Rob Renner, the provincial environment minister, requesting a formal environmental impact of the Heartland Transmission Project.

RETA contends the study is necessary to address concerns surrounding the health effects of the power line and any potential impacts on wildlife and vegetation.

The Heartland Transmission Project is the biggest power line to be considered for the province of Alberta, said John Kristensen, a spokesperson for RETA.

"Of all the lines that need to have an environmental impact assessment, this is the one," Kristensen added.

However, officials with Alberta Environment told CTV news an assessment won't likely be ordered, calling the impact of transmission lines minimal.

"We don't actually require environmental impact assessments for transmission lines," said provincial spokesperson Jessica Potter. "We exempted those two years ago based on the fact we knew the impacts quite well."

The preferred route for the high-voltage line would run along the eastern edge of Edmonton to a substation north of Gibbons. An alternate route would run west of the city.