By Tom Still

MADISON – With a constancy that goes unnoticed by most people, crude and refined oil flows past us every minute, hour and day.

Millions of barrels move to and through Wisconsin daily via a mix of transportation modes that carry with them varying degrees of risk and efficiency.

Public perceptions of risk matter at a time when the flow of oil from Canada, Alaska and the Dakotas remains high – and when 15 percent of the nation’s crude oil imports are passing through a major terminal in Superior, Wis., on the way south and east.

Oil spills of any kind generate headlines and public concern. Whether the source is a transoceanic tanker, a river barge, rail cars, underground pipelines or trucks, major spills pose problems for people, wildlife, water and the land.

All of those transit systems are used routinely across the United States. Rail and truck shipments remain relatively small as a share of the total but have increased sharply in recent years. Pipeline transport has grown steadily and tanker shipments have declined.

Analysts agree none of those modes will go away so long as there’s a demand for oil. Most environmentalists regard the oil transport debate as “picking your poison,” but other experts who have weighed the pro and cons agree some forms of transport are safer and more efficient than others.

A Wall Street Journal analysis in September 2015 noted that pipelines delivered about 58 percent of the nation’s oil supply in 2014, boats about 37 percent, and rail and trucks just under 3 percent each.

Because trains and trucks often pass through urban or heavily traveled areas, they pose more risk per barrel transported – as evidenced by fiery train derailments in Quebec and Virginia. Tankers and barges can carry much more oil, but the potential for a massive spill is proportionately higher and water is notoriously hard to clean.

Pipelines don’t spill as often as other forms of transport. In fact, a major industry association claims a 99.999 percent safe-delivery rate. When pipelines do spill, however, they can unleash major amounts of oil if not caught in time.

That’s what happened with the 2010 Enbridge spill in Michigan’s Kalamazoo River, an accident that prompted a cleanup and a historic fine. It also led to massive investments elsewhere in pipeline replacement, repair and monitoring technologies. Last month, an administrator for the federal Environmental Protection Agency gave the Kalamazoo River’s spill zone a clean bill of health.

“We found absolutely no evidence of the oil spill, and when I say no evidence I don’t mean just the oil if you put your paddle in the water you’re not going to get anything; I mean if you’re looking at the banks, all that reconstruction work, you’re not going to see any oil. It looks natural, that habitat has been absolutely restored,” said the EPA’s Robert Kaplan.

With five pipelines and 400 employees and contractors in Wisconsin, Enbridge is easily the largest oil transport company operating in the state. Its Superior terminal receives 2.3 million barrels of crude oil per day and can store up to 9.5 million barrels on site. Existing Wisconsin pipelines cover 1,552 miles and planned upgrades will modernize a significant portion of the system.

People who don’t live near oil pipelines usually don’t know the extent of the system, but those who live or work within range of a line likely do, even if it’s largely underground. Enbridge recently asked Sunseed Research LLC, a Madison public opinion firm, to assess how people in both camps view the risks and rewards.

About 63 percent of the general public surveyed by Sunseed viewed pipelines as the safest way to transport oil, compared to 73 percent of those who lived in one of four communities adjacent to pipelines (Jefferson, Hayward, Marshfield and Portage) and 80 percent of the landowners who live along pipeline right-of-ways. With familiarity apparently comes some measure of confidence.

Those same demographic groups ranked Great Lakes ships and barges, rail shipments and truck transport as generally less safe than pipelines, a finding that mirrors some national views.

No system of transporting oil is foolproof or even close. Until society’s need for oil goes away, however, investing in transportation systems that pose the least risk to people and the environment is the safer bet.