PRINCE GEORGE, B.C - A coalition of 11 environmental groups have asked Ottawa for a broad public inquiry into Enbridge's (ENB:TSX) proposed $4.5-billion pipeline through northern B.C.

Currently, the pipeline is to undergo a joint review by the National Energy Board and the Canadian Environmental Assessment Agency.

But the environmental groups said this week that won't adequately address "big picture" issues like greenhouse gas emissions from expanded oil sands production, the significant risk of tanker traffic on the coast and the cumulative impact of further pipeline and tanker traffic in the future.

Conservative Cariboo-Prince George MP Dick Harris reacted cautiously to the call for a public inquiry, but said he believes that companies face higher scrutiny than ever through the lengthy review process for large industrial projects.

Roger Harris, an Enbridge spokesman, said some of the environmental groups' assertions are simply not true.

He noted that the joint review panel's draft terms of references include consideration of oil tanker transport on the B.C. northwest coast, as well as the cumulative environmental impacts of Enbridge's project and others.

In a letter sent to Prime Minister Stephen Harper, the environmental coalition said the pipeline raises significant environmental, legal and economic issues.

"In our view, a project of such sweeping magnitude calls for a decision-making process that is similarly broad in scope -- one that honours the laws and responsibilities of First Nations, addresses the perspective of all affected communities, and considers the project in the context of the much larger policy questions that are raised by the prospect of an oil pipeline and oil tankers on the coast," the letter says.

The environmental coalition includes urban-based organizations like West Coast Environmental Law, the Dogwood Initiative, the Pembina Institute and ForestEthics, as well as northern B.C.-based groups like North West Watch, the Headwaters Initiative and the SkeenaWild Conservation Trust.

Josh Paterson, a lawyer with West Coast Environmental Law, said the intention is not to tell people what to think of the project, but to ensure British Columbians have a chance to make an informed decision about the project.

"In a region where salmon is so important, in a region that really depends so much on its environment, both for economics, but also for lifestyle, a project that brings this much risk for such a little amount of gain attached to it, should really be looked at skeptically," he said.

The proposed 1,170-km pipeline would carry oil from Alberta's tar sands through northern B.C. to Kitimat, where it would be loaded on tankers for shipment to the U.S. west coast or Asia.

Asia offers an alternate market for oil from Alberta. Almost all Alberta oil flows to the U.S. via pipelines.

The proposed pipeline travels near Prince George, at Bear Lake, and will cross more than 1,000 rivers and streams.

Harris noted that as industrial projects like Enbridge's pipeline move forward, they inevitably attract protest from group's that will use any method to put a stop to them.

Harris said a public inquiry would likely hold the project up.

"I know that a company like Enbridge does not for a minute believe they can get anything through the easy way. They do their homework, and they know the regulatory requirements, they know the environmental law, and they know they have to meet them before they can get past the review panels and the final word on their project," observed Harris.

Harris also noted that public inquiries don't normally have binding conclusions.

"Make sure what you are looking for is what you get. . . . You may end up picking a process that doesn't work for you," said Harris, who resides in Terrace in B.C.'s northwest.

Enbridge had shelved the project in late 2006, but put it back on the front burner early in 2008 after securing $100 million from Western oil producers and key Asian refiners to get the project through the regulatory process.

Key issues in the complex project - described by Enbridge as the largest crude oil pipeline expansion in North America - include mountainous terrain, the hundreds of river crossings and a tanker terminal at Kitimat.

Thousands of workers will be needed during the estimated three-year construction period, but relatively few when complete.

It's estimated that 50 permanent workers in Kitimat will be needed and a handful of workers along the route.

Enbridge has said it plans to file its environmental application this year.

A two-year assessment timeline -- should the company get approval -- puts the start of the three-year construction period beyond 2012.