By a 7-2 vote, Kelowna city council has agreed to allow Costco to use a mobile rock crusher for up to three months on the site of its new store.

Costco's request to use a mobile rock crusher at its new Kelowna site is drawing opposition from nearby residents.

Critics worry about the noise, dust, and vibrations they say would be generated by the mobile rock crusher and they're appealing for the city to reject Costco's plans.

"I did not move next door to a gravel pit, so I don't know why they should be allowed to crush rock on their property," Brandon Kehoe writes in a typical letter of objection received by the city.

"The residents that live in the vicinity of the building site of the future Costco have already had to deal with the noise of the heavy machinery and dust. To add further insult, we are now expected to have to listen to the even louder noise of a rock crusher and even more dust," writes Anette Stembridge.

Site work is underway at the new Costco location, between Baron Road, Springfield Road, and Leckie Road.

Costco says there are big boulders on the property and company representatives will ask city council for permission next Tuesday to bring in a mobile rock crusher, which is normally allowed only in industrial areas.

A special permit is being sought for the use of the rock crusher, for up to eight hours a day excepting weekends and holidays, for three months. An estimated 4,500 cubic metres of large rocks need to be removed from the site.

That volume of rock would require 320 dump truck loads if the material had to be hauled to a gravel pit for disposal, Costco says. The company says use of the mobile rock crusher would eliminate those trips, reduce greenhouse gases, and save wear and tear on local roads.

"Mitigation measures will be applied to reduce dust and noise and we propose that noise impacts (from the mobile rock crusher) will be no greater than other machinery used under accepted construction practices," a company agent writes in the application for the special permit.

But critics say Costco should have known what soil conditions were like at the site, and they say the request to use a mobile rock crusher is driven more by a desire to keep construction expenses low than regard for the environment.

"The traffic generated by tandem dump trucks hauling won't be any more of a traffic problem than when the new Costco is opened," Ron Ready writes in a letter to the city.

There are hundreds of homes in towers and condos near the new Costco site and many of the residents would have received direct notification by the city of Costco's request to use a mobile rock crusher.

As of Tuesday, 12 people had written letters of objection to the plan and three people had written letters in support.

"It would be preferable to many trucks adding to the busy area already. No matter what is done, the noise and dust will be there, so let's do it efficiently where possible," Fred and Cheryl Wiltse write in support.