It shall be unlawful to place or spill without immediately cleaning up any material or debris on a public street or sidewalk. It shall also be unlawful for the driver of any vehicle to track mud or dirt onto a public street. Upon notification by the city of any violation of this provision, the violator shall within twelve (12) hours clean the street or shall be liable to the city for the costs of doing so. The provision prohibiting the placement of materials on the public street or sidewalk shall not apply during cleanup periods established by the city, provided the materials are placed according to any directions of the city and do not obstruct traffic; nor shall the provision apply to persons doing work authorized by the city that requires the placing of materials in the street. (Ord. 2-2-94A, 2-2-1994)