The Bureau of Water Works is authorized to establish wellhead protection areas in order to regulate the storage, handling, use and transportation of materials that could contaminate groundwater. The Bureau of Water Works shall establish the boundaries of wellhead protection areas based on the best available information about the dynamics of the aquifers that existing and future wells tap, the time-of-travel of hazardous materials and other relevant factors. The Bureau shall publish a map of all designated wellhead protection areas, shall certify copies to other city bureaus, and shall make such maps available to the public upon request and otherwise take steps, in its discretion, to publicize the availability of the maps to residences and businesses within the wellhead protection area. The Bureau of Water Works may alter the boundaries of a wellhead protection area if the information on which existing boundaries are based changes. Proposed changes to a wellhead protection area shall be adopted by rulemaking.