Efforts are still underway to contain the flow of oil moving down the Kalamazoo River. But some environmental groups are concerned about more than just the oil. Over the past decade, organizations like the Kalamazoo River Watershed Council have worked to improve the condition of the river. Contaminants called polychlorinated biphenyls, or PCBs, are left over from years of industrial and sewage dumping in the river. WMUK's Maureen Savage has more:

Jeff Spoelstra is the coordinator of the Kalamazoo River Watershed Council. Spoelstra says there's been some speculation, so far unverified, that PCBs in the river might react with the oil floating by. If that happens, the PCBs could break loose and float farther down the river.

Spoelstra says his group's biggest concern is the long-term effects the leak may have on the river and surrounding wildlife. He says the Kalamazoo River spill may be the biggest incident of its kind in the Midwest.

Some are worried about oil seeping into groundwater drinking supplies, although state and federal officials say they don't expect that to happen. Some residents in Calhoun County with private wells near the river are getting supplies of bottled water paid for by Enbridge Energy Partners, the Canadian company that owns the pipeline that burst near Marshall earlier in the week. Because of high water levels on the river caused by recent storms, Spoelstra says oil and other pollutants may hurt wildlife and, possibly, humans if they eat contaminated fish and vegetation.

Federal, state and local officials urge people to stay away from the affected area of the river from Talmadge Creek in Calhoun County west to Lake Morrow in Kalamazoo County.

People interested in donating time any money to the recovery effort can join a page on Facebook.