A highway near Hamilton, Ont., was blockaded for almost 90 minutes Monday morning as a group stopped traffic to protest Enbridge's plan to reverse the flow of its pipeline that cuts through a rural area of Hamilton.

About 40 protesters staged a mock oil spill and cleanup on Highway 6 near Concession Road 6 to express their concerns about the pipeline. Six Ontario Provincial Police cruisers and two Hamilton police cruisers arrived at the scene shortly after the protest started at around 11 a.m. Police let some cars through after about half an hour. The road reopened around 12:30 p.m.

Protester Elysia Petrone, of Hamilton, said area residents are upset that the federal government has gone to extreme lengths to shut down public debate on this pipeline.

"Currently, the only body overseeing this reversal is the National Energy Board, and they've basically excluded any conversation about climate change, the tar sands and whether or not oil will be exported for consideration," Petrone added.

"They get to pick and choose who gets to have a say on this."

Many people aren't even aware of Enbridge's plan, Petrone said.

"A lot more people know about the Keystone XL project when we have the same deal on our back yard."

Enbridge pipeline reversal approved

Last year, the National Energy Board granted approval for Enbridge Pipelines Inc. to change the flow direction of the Line 9A pipeline, which runs oil from Sarnia to Hamilton. This would change the flow from westbound to eastbound. It is now seeking approval to change the flow of Line 9B, which cuts through Hamilton.

A hearing on the issue is scheduled for the week of Aug. 26.

Protesters worry that the flow reversal could raise the risk of a spill into the Beverly Swamp in the headwaters of Spencer Creek, Hamilton's largest watershed.

Some drivers were not sympathetic to the protesters.

"You stopped us regular folk from working. Good job guys," said one man stopped in his truck.

Line 9 built in 1975

Line 9 was originally built in 1975 to transport crude oil from Western Canada to Montreal refineries, in an eastbound direction. Thirteen years ago, the pipeline flow was changed to bring imported oil into Ontario.

When the flow reversal occurs, opponents worry there is a possibility of accident or malfunction of the pumps inside the pipes, which could cause a spill.

On Sept. 29, 2001, Enbridge Line 10 — which runs from Hamilton to Buffalo — ruptured in a soybean field.

According to a Transportation Safety of Canada report, the spill was a result of a communications failure between a pump station in Tonawanda and a control centre in Edmonton. The Tonawanda station's failure alarm didn't go off when the rupture occurred.

More recently, Enbridge has experienced pipeline spills in the Kalamazoo River in Michigan and in northern Alberta. This kind of history worries protesters.

Enbridge says 'no cause for concern'

Graham White, a media representative for Enbridge, said the company has been making an effort to be clear and informative with municipalities and other stakeholders in the reversal proposal. White said the company has planned to do extensive integrity digs in order to make sure the pipeline is in good condition.

"Anything that causes us concern, or may cause concern far down the road, we will go to this location, we'll dig down to the line, we expose the line and do a number of other tests, just to ensure that there is no cause for concern," said White. "And if there is, we would do any repairs or maintenance that is necessary."

White added that Enbridge is prepared to deal with an emergency if one were to occur, such as the pipeline breach in 2010 in Michigan.

He said Enbridge has a series of extensive preventative and reactive measures in place, and said the company has spent $50 million between 2012 and 2013 to improve its equipment, training, and overall emergency response capabilities.

"When you look at the worst case scenario — and certainly, the Marshall spill in Michigan in 2010 qualifies for that — we've made tremendous improvements and progress since then as a company," said White.

He added that the company spent $850 million on cleanup efforts in Marshall. "We have taken full responsibility for that incident, also in terms of costs."

White said there is a 24-hour, seven day a week continuous monitoring system in place, as well as emergency equipment nearby along the pipeline.

No charges were laid at the protest scene, said Sgt. Dave Woodford from the Ontario Provincial Police.

There's "always that possibility" that some might be in the future, but Woodford said he's not aware of any.

The protest was unexpected for the OPP, Woodford said.

"Lot of times when people protest, they advise us of what they're doing and we'll have proper officers in place," he said.

But today, "we didn't know prior to the protest."