WATERLOO -- Black Hawk County has brought a rural mining operation in line with the zoning ordinance.

Members of the county Board of Supervisors voted unanimously Tuesday to rezone the Zeien Sand and Gravel operation from agricultural to ag-limited. The site, along La Porte Road about a quarter mile north of La Porte City, had been operating as a "legal nonconforming" use because it was in business before the zoning ordinance was adopted.

BMC Aggregates Inc. recently exercised an option to lease the mining operation and wanted to correct the zoning before moving ahead.

"Nothing really is going to be changing other than who is running the sand operation," said county zoning administrator Shane Graham.

The Planning and Zoning Commission had unanimously recommended the zoning change and no objections were raised by neighbors.

BMC geologist Sherman Lundy said there is a 50- to 75-year supply of sand used in the asphalt process available on the site.

In other business, the supervisors unanimously approved a $64,832 bid from All Iowa Contracting Co. of Waterloo to paint pavement markings at various locations on rural county roads. A second bidder failed to submit a required bid security, leaving All Iowa as the only legitimate bidder.

Contact Tim Jamison at (319) 291-1577 or tim.jamison@wcfcourier.com.