Did Komatsu Do Enough to Contain the Menomonee River Oil Spill?

We investigate if more could have been done to limit the effects of the December accident.

When oil is spilled, time is of the essence. Once petroleum products hit water, a spill’s potentially devastating effects on the environment and wildlife are very difficult to predict and control.

Months later, questions remain as to how quickly and effectively the manufacturing company Komatsu responded to contain the 400 gallons of oil it spilled into the Menomonee River in December.

The accident, initially believed to be a relatively small spill of waste oil from a container outside Komatsu’s mining equipment factory in West Milwaukee, has had wide-ranging effects on local waterways and wildlife, the full extent of which still hadn’t been determined even after the spring thaw.



Join us for a free webinar on Dec. 7 about year-end financial planning including: account management, credit needs and taxes. Register for expert tips today

Photo courtesy of Milwaukee Riverkeeper
Photo courtesy of Milwaukee Riverkeeper

Oil began polluting the Menomonee River on Dec. 3, when Komatsu employees admittedly mishandled a transfer between two tanks. The oil surged into the waterway through a stormwater drain.

The spill, the equivalent of eight 50-gallon drums, spread quickly. Eventually, residents of upper-level condos in the Third Ward began seeing the oil sheen – difficult to spot from surface level – downstream in the Milwaukee and Kinnickinnic rivers, as well as their shared outlet to Lake Michigan. 

“It’s not rare to have industrial spills into local rivers, but this was a large spill,” says Milwaukee Riverkeeper’s Cheryl Nenn, who patrols Milwaukee’s rivers identifying sources of pollution. “It’s not the Exxon Valdez, but a lot of oil spilled into a fairly small river. It’s pretty rare to have this much product covering such a wide geography.”

When Komatsu discovered the seriousness of the situation, it implemented what it called an “aggressive cleanup and remediation effort” that eventually included as many as 250 absorbent booms and vacuums to collect contaminated water.  

Nenn and others who were seeing evidence of the spill became increasingly frustrated as days passed before the source of the spill became public. “We were just trying to figure out what was going on,” Nenn says.

Photo courtesy of Milwaukee Riverkeeper

Komatsu, for its part, immediately notified the Wisconsin Department of Natural Resources and the U.S. Environmental Protection Agency. “They did what was legally required but they didn’t go beyond that,” Nenn says. “They could have done a better job of letting the community know.” 

Among the immediate steps Komatsu should have taken would have been to call 911 so that a Milwaukee Fire Department emergency response team trained to deal with such situations could have been dispatched, Fire Chief Aaron Lipski said at a Milwaukee Common Council committee meeting in January. Port Milwaukee also could have acted immediately with boats and staff but didn’t learn of the spill until a week later.

Several weeks after the spill, Komatsu continued to conduct daily inspections while maintaining a series of booms on the waterways to absorb any additional sheen. “The spill involved light, used oil that was already diluted with water and thus remained on the surface of the river, making it easier to identify and remove,” Komatsu spokeswoman Caley Clinton says. 

In late March, Komatsu deemed its cleanup efforts complete. “Through our continued assessment, and as verified by an outside third-party expert, the work to restore the waterways to pre-spill conditions is complete to the extent practical,” Clinton said at the time.

Anabelle, a snowy owl, was injured in the spill; Photo courtesy of The Wisconsin Human Society

As of early spring, the DNR’s investigation of the incident remained active. “Any spill is concerning to the department. We take all of them seriously,” DNR regional spills coordinator Riley Neumann says. “We continue working with Komatsu to restore the environment. State statutes require that the company restore the environment to the extent practicable.”

The spill did have victims; several oil-covered Canada geese were seen in the area immediately after the spill, Nenn says. Wildlife volunteers rescued one, along with an oil-covered snowy owl. Both recovered after being treated at the Wisconsin Humane Society’s Wildlife Rehabilitation Center. The spunky owl, named Annabelle by those who treated her, spent 93 days at the center before being set free to fanfare in March.

After a 93-day recovery,  Anabelle was released into the wild; Photo courtesy of The Wisconsin Human Society

Komatsu posted that it had provided support to the Humane Society for costs related to the rehabilitation of the birds, though it has declined to specify how much it has spent on the larger cleanup and restoration effort. It says it’s working on “corrective measures, policies and procedures” to prevent spills.

“We sincerely regret that this incident occurred and continue to express our deep and sincere apologies to the community,” Clinton says. “The spill itself is something that never should have happened, and we remain committed to enhancing our procedures so this doesn’t happen again. We’ve learned a great deal through this process about stakeholder communication and are committed to doing better moving forward.”

Production at Komatsu’s West National Avenue plant eventually will be transferred to the company’s sprawling new $285 million manufacturing campus in Milwaukee’s Harbor District. Clinton says the campus has multiple levels of containment and controls for the use of liquids on site. It has no direct stormwater connections and is designed to prevent runoff into the river or harbor through the use of biobasins and bioswales that capture and naturally filter stormwater.

Preventative measures are key, Nenn says. “It’s really hard to deal with this once the oil is in the water,” she says. “This never should have happened. and we want to make sure it never happens again.” 

Listen to WUWM’s “Lake Effect” May 11 at noon to hear more about this story. 


This story is part of Milwaukee Magazine‘s May issue.

Find it on newsstands or buy a copy at milwaukeemag.com/shop

Be the first to get every new issue. Subscribe.



Rich Rovito is a freelance writer for Milwaukee Magazine.