On Jan. 17, an oil pipeline leaked an estimated 50,000 gallons of crude oil along the Yellowstone River near Glendive, Montana. The incident contaminated the town's municipal water system, highlighting the risk of building pipelines near water sources and elevating concerns about the proposed Keystone XL pipeline.

The Poplar Spill

The Poplar Pipeline system that leaked carries Bakken crude oil from the Canadian border to southern Montana. The pipeline crosses beneath the Yellowstone River, one of the major tributaries of the Upper Missouri River. Saturday’s leak occurred in the segment that crosses beneath the river, spewing crude directly into the Yellowstone.

Crude oil from the leak was detected as far away as Sidney, Montana, 60 miles downstream. On Sunday, Glendive residents reported smelling gasoline in their tap water. Testing confirmed contamination of Glendive’s water supply, and the city issued a drinking water advisory. Trucks are now shipping water to the town’s residents.

Bridger Pipeline LLC owns the Poplar Pipeline system and is currently investigating the incident. Icy river conditions are complicating cleanup, as crews must drill holes into the ice in order to suction out oil.

A Leaky History

This isn't the only pipeline leak in Montana's recent history. In 2011, a pipeline ruptured underneath the Yellowstone River near Billings, Montana, polluting its waters with 63,000 gallons of crude oil. It cost $135 million to clean up the river, and operator ExxonMobil paid $1.6 million in state fines.

Oil and gas pipeline leaks are not rare. In fact, they happen nearly every day in the United States. The U.S. Pipeline and Hazardous Materials Safety Administration reported 620 incidents in 2013, resulting in 10 fatalities and costing over $336 million in damages.

Why are accidents so frequent? Some may be caused by aging infrastructure. Almost half of the crude oil pipelines in the U.S. are more than 50 years old, meaning they are more susceptible to leaks and failures. But that doesn’t mean new pipelines are risk-free; the Keystone I pipeline connecting Canada to Illinois reported 14 leaks during its first year of operation.

Another issue is oversight: the U.S. has 2.6 million miles of oil and gas pipelines but only 135 federal pipeline inspectors. State partners contribute an additional 375 inspectors, but that’s nowhere near enough to detect issues and prevent pipeline spills. The Poplar Pipeline had not been inspected since 2012.

Oil industry apologists point to new leak detectors and other pipeline technologies that are supposed to alert officials to potential problems. However, fewer than 20 percent of incidents are first detected by this technology. Instead, nearby residents and workers are three times more likely to notice problems first, often after leaks are well underway.

Given aging pipelines, scarce inspectors, and technology that fails to detect problems, transporting oil by pipeline is a risky business. And disasters pollute our rivers and threaten farmland and wildlife habitat.

Keystone XL

Despite the frequency of pipeline incidents, Congress is expected to pass a bill to try to force the Obama administration to approve the Keystone XL pipeline, a project that connects Canadian tar sands crude with refineries along the Gulf of Mexico. That oil is destined for the export market, so it will not increase U.S. oil supplies, but it will threaten U.S. farmland, wildlife habitat, rivers, and groundwater sources adjacent to its 1,179 miles of piping.

The Keystone XL pipeline is three times wider than the Poplar pipeline, meaning it carries more oil and poses an even greater threat to surrounding areas in the event of a spill. Keystone XL will run directly above Nebraska’s Ogallala Aquifer, a shallow aquifer that provides drinking water to two million Americans. A Keystone pipeline spill could easily seep into the water table and pollute the aquifer. Keystone XL would also cross under both the Yellowstone River and the Missouri River, risking contamination of wildlife habitat and numerous municipal water supplies.

Saturday’s oil spill is a stark reminder that pipelines pose a significant, immediate risk to public health and our natural resources. We can find other, safer sources of energy that do not threaten American water supplies. Let us hope the Obama administration understands this and does not allow the Keystone XL project to advance.