All improved residential property, purchased prior to December 31, 2020, is hereby exempted from a portion of the County property tax in accordance with Section 9-318, Tax-Property Article, Annotated Code of Maryland, provided that the improved residential property is: Located within the defined Landfill Impact Zone dated April 2021 which includes current partial property tax credits totaling 41 units, plus the inclusion of additional residential units within the defined limits of the Landfill Impact Zone and totaling 2,080 units; or Within the area defined as the Landfill Impact Zone, and generally described as beginning at Largo Road at White House Road, southerly to opposite Kent Drive, westerly to Brooke Lane at Brown Station Road, continuing to Ritchie-Marlboro Road, northerly to White House Road, and crossing to McCarthy Drive and north of Heartland Court, easterly to Harry S. Truman Drive, northerly to Southwest Branch Western Branch waterway, which completes the enclosed area at the waterway crossing under White House Road near Largo Road. The partial property tax credit shall be granted for the full fiscal year following any portion of the immediately preceding fiscal year in which landfilling operations commence or continue pursuant to a State refuse disposal permit and shall be granted annually as long as the Brown Station Road Sanitary Landfill operates. The partial property tax credit shall be payable from the site development and environmental surcharge collected pursuant to Section 21-123 and shall be in an amount equal to the average cost of refuse collection for the eligible property. During any fiscal year, the total of all tax credits granted under this Section shall not exceed Six Hundred Thousand Dollars ($600,000). The partial property tax credit authorized on the existing 41 units plus the additional 2,080 residential units within the defined limits of the Landfill Impact Zone shall appear as a credit on the annual residential property tax bills of property owners. The application of the tax credit shall be reviewed with each update of the Ten Year Solid Waste Plan for the purpose of expanding the Brown Station Road Impact Zone consistent with a proposed expansion or extension of the Brown Station Road Sanitary Landfill.