By Mary Lou Aurell

Media focus on the big ones, like the 1989 Exxon Valdez oil spill in Alaska’s Prince William Sound and its horrific effects on the environment.

However, the U.S. Environmental Protection Agency (EPA) claims that freshwater spills are more frequent and often more destructive because they can contaminate drinking water and the nesting grounds and food sources of freshwater organisms, plants, animals, birds and fish.

The EPA and the Air & Waste Management Association (AWMA) present a litany of freshwater spills’ harmful effects that can work their way up the food chain with terrible consequences.

The 1991 Lakehead Pipeline spill near Itasca Community College that poured 630,000 gallons of crude into a wetland and the Prairie River, as well as the quarter of a million gallon Enbridge spill near Cohasset that flooded a marsh in 2002, could have been disastrous, but they weren’t as bad as they might have been because of the “armada” of cleanup crews.

Cleanup is critical to reducing the contamination of ground water. Luckily, when the Lakehead spill happened the ground was frozen, as was most of the river, which contributed to a more thorough cleanup that saved the ground water and the Mississippi River.

How badly a spill harms the environment depends on whether the oil is in flowing water like the Prairie River or in standing water, like the Cohasset marsh.

A river’s currents provide a natural cleaning mechanism that moderates a spill. Still, the EPA says that freshwater organisms may be smothered by oil carried by a current or slowly poisoned by long-term exposure to oil trapped in shallow water or stream beds.

A DNR Division of Fisheries and Wildlife follow-up study has shown that river mussels living in the Prairie River do not appear affected, according to Chris Kavanaugh, DNR Area Fisheries Supervisor.

However, standing oil is still seen in the nearby wetland, said Biologist Harry Hutchins.

The Mississippi was saved again when booms and a controlled burn prevented the Cohasset spill from reaching it. But wetland damage was inevitable because parts of it had to be filled in to reach the spill. The damaged swamp was replaced with a new wetland created south of Warba.

Kavanaugh said that because the Cohasset spill was recovered so quickly, fish were not affected.

The ruptured Enbridge pipeline that sent a half million gallons of oil onto porous sandy soil northwest of Bemidji in 1979 reached an aquifer. About 60% was recovered. The MPCA said that leaving the rest in the ground was acceptable, according to a 2007 MPR NewsQ article. However, Enbridge continued to pump petroleum from the water table, remove contaminated soil and plant trees to replace those coated with oil. Nearly ten years later, the MPCA insisted that Enbridge get as much of the remaining oil as they could out of the ground. They pumped until 2004 when it became too costly to continue.

A later U.S. Geological Society study stressed the importance of long-term monitoring of this spill because it had touched an aquifer.

Another water table was contaminated in a northern Wisconsin Enbridge spill, according to a 2007 Milwaukee Journal article.

And a 2008 Journal piece cited 100 allegations made by the Wisconsin DNR relating to environmental harm caused by pipeline construction. “Enbridge workers illegally cleared and disrupted wooded wetlands and were responsible … for sediment being discharged into waterways,” reported Lee Bergquist.

Enbridge spokeswoman Denise Hamsher admitted to some major erosion near streams and said that restoration would leave little evidence of pipeline construction, Berquist wrote.

Enbridge is now building two major pipelines that will pass through the Grand Rapids and Bemidji areas. The lines will cross 242 bodies of water and many acres of wetland. One of these rivers is the Pokegama River that begins near Jay Cooke State Park on the Minnesota/Wisconsin border. Its wetlands are considered “an endangered resource.”

When a pipeline crosses stream or river there is potential for oil spills, said Bob Leibfried, NE Eco Regional Manager in the DNR Division of Ecological Resources. “We have to choose a route with the least risk to protect our water resources,” he added.

Enbridge does have a comprehensive spill prevention plan that is considered the best in their industry.

However, there is another construction problem: freshwater pollution may be caused by the bentonite pipeline workers use during drilling. “It can find its way into flowing water and affect fish health,” Leibfried noted.

But, let’s not place all of the blame for environmental damage on the Enbridges. If you add up all of the oil dumped on the ground in a year by individuals changing oil, it would equal or surpass a serious oil tanker spill, revealed the AWMA.

RELATED STORIES:

Pipeline Series: Ebridge Pipeliners are Back in Northern Minnesota
Pipeline Series: Oil Spills Smear Pipeline Companies' Reputations