When the City of Pella needs a pothole fixed, Public Works Director Denny Buyert says they also have two options depending on the weather. The top choice for workers is a hot mix that can only be used between April 15th and November 15th, and costs $60 a ton. The other option, a cold patch called UPM, is $140 a ton. Byart says that city workers are always on the lookout for holes, but if you see one that needs tended to, you can call Public Works in Pella at 628-1601.