The "Brownfield Revitalization and Remediation Act" seeks to restore and significantly expand the tax expensing of qualified environmental remediation expenditures under the Internal Revenue Code of 1986. It retroactively re-enables the expensing provision for costs incurred between 2012 and 2024, and extends its availability until the end of 2029, providing a renewed incentive for cleanup efforts. Furthermore, the bill broadens the scope of eligible expenditures by explicitly including reasonable costs for the assessment, investigation, and monitoring of contaminated sites. It also creates a special rule allowing the expensing of depreciable property at brownfield sites, which was previously disallowed. Finally, the definition of qualifying substances is expanded to include any pollutant or contaminant as defined by the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), encouraging more comprehensive site cleanups.