Despite strong objections from neighboring landowners and the city of Eudora, Douglas County commissioners gave final approval Wednesday for a sand pit mining operation along the Kansas River.

The decision helps clear the way for Penny’s Concrete Inc. to move one of its current dredging operations out of the Kansas River and onto the south bank, where it would mine sand on about 166 acres of land northwest of Eudora, near North 1500 Road and East 1850 Road. The plan still needs approval from a number of state and federal authorities.

Penny’s sought the permit after the U.S. Army Corps of Engineers declined to renew the company’s permit for the in-river dredge near that site.

The 2-1 vote came after another lengthy public hearing — the third in the past year — during which opponents argued it could threaten private and municipal water supplies in the area, while company officials insisted the sand pit would pose little or no danger to public health and safety.

“This affects over 6,000 people in our county — the city of Eudora, and even people outside the city who buy water from us,” Eudora Mayor Ruth Hughes said. “What we really need is to just say no to this.”

Earlier in the week, the Eudora City Commission voted unanimously to urge county commissioners to reject the permit. Their concern was that the pit mine, and the lake it will create, could act as a pathway for contamination to affect the city’s water supply.

But the county had already given preliminary approval in March, subject to an engineering study to determine if the sand pit would threaten either the quality or quantity of water in the aquifer beneath the site.

Richard Murphy, an engineer with Conestoga-Rovers and Associates, which performed that study, said water in the aquifer generally flows northeast, away from Eudora’s wells. And while he conceded that the mining operation could alter the flow and direct some water to the city’s wells, he said there were enough protections built into the conditional use permit to protect the people of Eudora.

“I would feel very comfortable with the water supply, yes,” Murphy said, when asked how he would feel if he and his family lived in Eudora and drank municipal water.

Commissioner Nancy Thellman sided with Eudora officials.

“I stand with the city,” Thellman said. “I agree with the mayor. This is a risk that’s too big.”

But Commissioners Mike Gaughan and Jim Flory said they were satisfied that the conditions of the permit would minimize the risk.

“I’m confident that the Conestoga-Rovers information is accurate and appropriate,” Flory said. “They feel as long as the conditions we’re setting are carried out, this can be a safely run operation and not impact the water supply of the city of Eudora.”