Douglas County commissioners gave preliminary approval Wednesday night for Penny’s Aggregates to develop of a sand pit dredging operation along the south bank of the Kansas River near Eudora.

Meanwhile, a representative from Penny’s offered assurances Wednesday that the company would promptly address one major concern of nearby property owners: the noise being generated by the company’s existing dredge in the channel of the river.

Melanie Lorenzo, director of operations for the company, told commissioners the company has ordered mufflers for the diesel engine exhausts of the dredge and would install them as soon as they arrive, possibly within the next week.

In addition, if the county eventually grants the permit, one of many conditions will be that it maintain mufflers on the dredge and limit the hours of operation from 6:30 a.m. to 6:30 p.m., Monday through Friday.

The sand pit would be located on about 434 acres at the northeast corner of North 1500 Road and East 1850 Road. The property is owned by Penny’s Concrete and Van LLC. The sand pit dredge, however, would be operated by Penny’s Aggregates.

The 2-1 vote authorizes the next step in the process, hiring an independent third-party consultant to conduct an in-depth study to determine any potential threats that such a sand pit would pose to the underground aquifer that serves as the main water supply for the city of Eudora and several nearby landowners.

Nancy Thellman, the lone dissenter in the vote, tried unsuccessfully to attach more conditions to the permit and to request even further studies. She had said throughout the process that the sand pit would destroy valuable agricultural land.

But commission Chairman Mike Gaughan said he believed authorizing the sand pit would help protect another valuable resource, the river itself.

“The (U.S.) Corps of Engineers is moving this stuff off the river, and we should view that as a victory,” Gaughan said after the meeting. “It strikes me that is just as much of a resource that we should value as the soil and sand.”

If that study, which could take about three months to complete, shows the sand pit would pose no significant threat to those water supplies, the county has committed to issuing the conditional use permit. However, the county reserves the right to attach additional conditions to the permit, or to deny the permit altogether if the pre-dredging report shows it would pose a serious threat to those water supplies.

In November, after the first of two lengthy public hearings before the commission, the county hired a consultant to review all the geological reports that had been filed in the case and make a recommendation.

That firm, Conestoga-Rovers and Associates in Topeka, issued a report in January saying the sand pit likely would not pose a significant threat. But it recommended conducting a more thorough analysis, including drilling test wells to get baseline measurements of the current water quality and to require continued monitoring of the water as long as the sand pit operates.

At one point, Thellman challenged that firm’s objectivity and suggested the county should hire a different firm to conduct the pre-dredging analysis.

“I was taken aback at the last meeting when (representatives) of Conestoga-Rovers made statements that seemed clear to me that their presumption is that the project should go forward,” Thellman said.

Both Gaughan and Commissioner Jim Flory disagreed.

“It’s difficult for me to say they don’t represent us when we hired them,” Gaughan said. “The answer they gave may not be what you wanted it to be, but we chose them. Their reputation isn’t on trial tonight.”

Company officials have said even if the county eventually grants the permit, they will still need to obtain permits from several other state and federal agencies before the sand pit is allowed to open.