A $274 million pipeline project in Michigan is facing a massive hurdle of tiny proportions—a two-inch mussel.

The federally protected, endangered Northern Riffleshell mussel lives in the Black River in Sanilac County, MI, which falls directly in the path planned for a new pipeline designed to end the area's reliance on Detroit for its public water supply.

The mussels have prompted the U.S. Environmental Protection Agency to step in, objecting to a wetlands permit and putting a temporary kibosh on the 80-mile-long raw water pipeline project.

Karegnondi Water Authority

Several areas in Michigan are awaiting the construction of a $274 million, 80-mile-long water pipeline to eliminate their dependence on water from Detroit.

The purpose of the project is to supply drinking water from Lake Huron to the City of Flint Water Treatment Plant for the Karegnondi Water Authority (KWA).

KWA is a Municipal Water Supply System that consists of the Genessee County Drain Commissioner, Lapeer County Drain Commissioner, Lapeer City, Sanilac County Drain Commissioner, and the City of Flint.

Permit Objections

Once found in several major river systems throughout Michigan, the Northern Riffleshell is now only in the Black, St. Clair, and Detroit Rivers, the state's Department of Natural Resources reported.

The mussels require a stable, undisturbed habitat and a sufficient population of host fish, according to the U.S. Fish & Wildlife Service.

Construction for the pipeline project will temporarily impact more than 31 acres of wetlands and cross 55 waterways, according to the Michigan Department of Environmental Quality.

The EPA sent a letter to the state DEQ in March, objecting to a wetlands permit. EPA said it was "concerned that there will be permanent loss of aquatic functions due to temporary impacts" on rivers and wetlands, according to the local media outlet MLive.com.

U.S. Fish & Wildlife Service

These federally protected mussels have temporarily stalled the project and could add $200,000 to its price tag.

Currently, several areas awaiting the pipeline buy water from Detroit and face increased rates of up to 15 percent per year, according to KWA.

Tacking on $200K

The federal objections could force KWA's contractor to tunnel deep below the river instead of using a simpler, open-cut process. An open-cut would allow the pipeline to be laid one section at a time by temporarily diverting the water.

Having to tunnel under the river could add about $200,000 and a week of work to the project, County Drain Commissioner Jeff Wright told MLive.com.

"It just comes down to which technique is least disruptive," Wright said. "EPA is going to let us cross the river, but they haven't decided which construction they want us to use. ... We expect to have an answer on that in the near future."

The state is expected to make its decision by June 15, after receiving advice from the EPA, MLive.com reported April 28.

'Confident' in Crossing

Sanilac County has submitted a response to EPA's objection to the permit, Chris Clampitt, an environmental quality analyst with the DEQ Water Resources Division, told MLive.com.

U.S. Army Corps of Engineers

The Black River is one few locations in Michigan where Northern Riffleshell mussels still exist.

The state won't be able to issue the permit until the EPA lifts its objections. However, Wright told MLive.com that he's confident the project won't be stalled because KWA will seek bids for the two possible ways to cross the river.

Construction on the section of pipeline in question isn't expected to start until September, and KWA has yet to request bids.

Snakes, Too

The U.S. Fish & Wildlife Service says it is also concerned that pipeline construction will affect the Eastern Massassauga Rattlesnake.

Clampitt told MLive.com the rattlesnakes are a "lesser concern" than the mussels. KWA has agreed to bring in an expert biologist to move any snakes and make sure they are not harmed.