The fee for a single-family property is the flat rate determined by:the applicable tier category within which the property falls, as determined under subsection (b) of this section; the number of equivalent residential units (or “ERUs”) assigned to that tier; and the rate per ERU set in accordance with § 3-4 {“Initial rates”} or <cite data-path="|27|§3-5">§ 3-5 {“Subsequent rates”} of this subtitle</cite>. The tier categories for single-family properties are based on a property’s impervious surface area, as determined by the Department of Public Works. The tier categories are as follows:Tier 1 – property with impervious surface area less than or equal to 820 square feet. Tier 2 – property with impervious surface area greater than 820 square feet and less than or equal to 1,500 square feet. Tier 3 – property with impervious surface area greater than 1,500 square feet. If a property owner contests the property’s tier assignment and presents plat information, non-aerial photography, or non-aerial videography to support a claim that the property belongs in a lower tier, the Department must:demonstrate that the higher tier is correct; or failing to so demonstrate, make the requested correction. Ord. 13-143