A proposal to develop an open-pit sand mining operation south of the Kansas River near Eudora will have to go back to the Lawrence-Douglas County Planning Commission for a new public hearing in January, delaying a final decision on the application by at least a month, county officials said Thursday.

Douglas County administrator Craig Weinaug said a technical error was discovered recently in the original public notice of the planning commission’s public hearing on the application in October.

“Specifically, two property owners in (Leavenworth) County who are within 1,000 feet of the operation were not notified,” Weinaug said.

As a result, he said, the county will have to send out new public notices and schedule another public hearing at the planning commission for either Jan. 28 or Jan. 30. He said the planning commission’s recommendation will then be sent to Douglas County commissioners, who will probably consider it later in February.

Penny’s Concrete and Sand is proposing to develop a sand pit mine on a 434-acre site near the south bank of the Kaw, near a site where the company currently operates a dredging operation in the river. The land is currently zoned for agricultural use.

Company officials have said they need the new operation, in part because of doubts about how long the U.S. Army Corps of Engineers will continue to issue permits for dredging sand within the river.

But nearby residents and the city of Eudora have objected to the proposal, arguing that the mining operation could threaten both the quality and quantity of underground wells that serve as the municipal water supply for the city and residential water supplies for the nearby farms.

The planning commission originally recommended approval of a rezoning request and conditional use permit for the pit mine, subject to numerous requirements aimed at preventing water contamination.

Douglas County commissioners considered the proposal Nov. 28 during a public hearing that included more than five hours of comments and more than 400 pages of written documentation. In the end, commissioners decided to hire an independent engineer to review the material and make a recommendation.

That report, by the engineering consulting firm Conestoga-Rovers & Associates, was posted on the county’s website Thursday, the same day Weinaug announced that the hearing process would have to be started anew.

“In summary, our review does not indicate there are any major problems or concerns with regard to the proposed operation; however we have several recommendations for further assessment to confirm this position and implement precautionary measures and best management practices for the operation,” the report states.

Among the additional requirements, the consultants recommended tests to determine the current groundwater and soil quality to provide a benchmark of conditions as they exist before the new mine opens, and continued monitoring of conditions after the mine begins operations.