Legislator Birnbaum Hosts Tax Grievance Workshops. Deadline to file a grievance is March 3rd. Nassau County Legislator Ellen W. Birnbaum (D-Great Neck) is hosting three workshops in February regarding the process of property valuation. The workshops will teach residents how to file an appeal of the assessed value of their property if they disagree with their most recent assessment. For more information, please call Legislator Birnbaum’s office at 516-571-6210 or Mehran Hakimian mehranhakimian@gmail.com. Click Here for workshop locations and hours