(a) At the time and place fixed for the appeal, whether at a triennial or inter-triennial assessment, the commissioners, acting as a board of revision, or the board for the assessment and revision of taxes, shall attend and hear all persons who may apply for redress, and grant such relief as to them shall appear just and reasonable: Provided, That the commissioners, acting as a board of revision, or the board for the assessment and revision of taxes, shall not make any allowance or abatement in the valuation of any real estate, in any other year than that in which the triennial assessment is made, excepting where buildings or other improvements have been destroyed, or where coal, ore, or other minerals assessed under the triennial assessment have been mined out, subsequently to such triennial assessment, in which cases such allowance or abatement shall be made.

(b) In any appeal of an assessment the commissioners, acting as a board of revision of taxes, or the board for the assessment and revision of taxes, shall make the following determinations:

(b.1) When a county has effected a countywide revision of the assessment which was used to develop the common level ratio last determined by the State Tax Equalization Board, the following shall apply:

(c) The county commissioners, acting as a board of revision of taxes, or the board for the assessment and revision of taxes, after determining the market value of the property, shall then apply the established predetermined ratio to such value unless the common level ratio published by the State Tax Equalization Board on or before July 1 of the year prior to the tax year being appealed to the county commissioners, acting as a board of revision of taxes, or the board for the assessment and revision of taxes varies by more than fifteen per centum (15%) from the established predetermined ratio, in which case the commissioners, acting as a board of revision of taxes, or a board for the assessment and revision of taxes, shall apply that same common level ratio to the market value of the property.

(d) Nothing herein shall prevent any appellant from appealing any base year valuation without reference to ratio.

(e) Persons who have suffered catastrophic losses to their property shall have the right to appeal before the county commissioners, acting as a board of revision of taxes, or the board for the assessment and revision of taxes within the remainder of the county fiscal year in which the catastrophic loss occurred, or within six months of the date on which the catastrophic loss occurred, whichever time period is longer. The duty of the county commissioners, acting as a board of revision of taxes, or the board for the assessment and revision of taxes shall be to reassess the value of the property in the following manner: the value of the property before the catastrophic loss, based on the percentage of the taxable year for which the property stood at its former value, shall be added to the value of the property after the catastrophic loss, based on the percentage of the taxable year for which the property stood at its reduced value. Any property improvements made subsequent to the catastrophic loss in the same tax year shall not be included in the reassessment described in this subsection for that tax year. Any adjustments in assessment under this subsection:

A reduction in assessed value for catastrophic loss due to inclusion or proposed inclusion as residential property on either the National Priority List under the Federal Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (Public Law 96-510, 94 Stat. 2767),¹ as amended, or the State Priority List under the act of October 18, 1988 (P.L. 756, No. 108),² known as the “Hazardous Sites Cleanup Act,” shall be in effect until remediation is completed.

(f) As used in this section, “catastrophic loss” means any loss due to mine subsidence, fire, flood or other natural disaster which affects the physical state of the real property and which exceeds fifty per centum (50%) of the market value of the real property prior to the loss. The phrase “catastrophic loss” shall also mean any loss which exceeds fifty per centum (50%) of the market value of the real property prior to the loss incurred by residential property owners who are not deemed responsible parties under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 or the “Hazardous Sites Cleanup Act” and whose residential property is included or proposed to be included as residential property on:

(g) Notwithstanding any other law regarding the assessment of real property due to catastrophic loss, the provision of subsections (e) and (f) relating to residential property affected by the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 or the “Hazardous Sites Cleanup Act” shall apply to all counties.