What's in those cone-shaped buildings?

On the east side of Grandview Boulevard just south of Woodburn Road, two cone-shaped buildings stand on a parcel of property owned by Waukesha County.

The buildings are salt sheds, designed to store the salt used by Waukesha County highway workers to de-ice county and state roads during the winter months. The big dome, which was built in 2009, holds 10,000 tons of salt, while the smaller dome, built in the mid-80s, holds about 4,500 tons.

Those two domes are located at the headquarters for the county's highway operations division. The county also has four other salt domes, each of which holds 3,000 tons of salt, at county public works sites in Nashotah, Sussex, New Berlin and North Prairie.

The county used to also have a sand storage shed at the Woodburn Road property, but it was torn down to make way for the big salt dome, said Highway Operations Manager Peter Chladil. While the county still has a few sand sheds at other county sites, sand typically isn't used on roads unless the county runs out of salt.

Cone-shaped buildings are frequently used to store road salt because they can efficiently accommodate the specific "angle of repose" of a salt pile. Salt has an angle of repose - the internal angle formed between the sloping side of the pile and the horizontal surface - of 32 degrees, according to Ned Zagorski, a construction manager with the Dome Corporation of North America.

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