TAZEWELL, VA (AP) A dozen tiny mussels are giving some southwestern Virginia officials a big headache.

The endangered Tennessee heelsplitters are causing Tazewell County officials to reroute a sewer line project along the U.S. Route 460 corridor, increasing its price by about $200,000. So far, 12 mussels have been found, but officials say more likely populate the Bluestone River in the construction zone.

The county also must help with the cost of moving the 12 endangered mussels upstream, County Administrator Jim Spencer said.

“It appears it will be a $150,000 to $200,000 increase in the cost,” Spencer said. “That is what we are estimating right now.”

The Bluefield Divides Sewer Project, which has been in the planning stage for more than a decade, was delayed following the discovery of the endangered mussels earlier this summer. But permits from the Department of Game and Inland Fisheries, the Marine Resource Commission and the U.S. Army Corps of Engineers have allowed limited construction work since then.

The permits from the three agencies only allow the contractor 75 days to work, but Spencer said officials still are optimistic that construction will be able to begin soon.

“We are still wanting to get started as quickly as possible,” he said.

The mussels aren’t the only environmental roadblock for Tazewell County officials in recent months. The Tan Riffleshell, Rough Rabbit’s Foot and the Purple Bean mussels all live in the Indian Creek of the upper Clinch River in Cedar Bluff, the location of a proposed natural gas line project.