diff --git a/app/jobs/migrations/normalize_geo_area_job.rb b/app/jobs/migrations/normalize_geo_area_job.rb
new file mode 100644
index 000000000..e5f8e7d1d
--- /dev/null
+++ b/app/jobs/migrations/normalize_geo_area_job.rb
@@ -0,0 +1,11 @@
+class Migrations::NormalizeGeoAreaJob < ApplicationJob
+  def perform(ids)
+    GeoArea.where(id: ids).find_each do |geo_area|
+      geojson = RGeo::GeoJSON.decode(geo_area.geometry.to_json, geo_factory: RGeo::Geographic.simple_mercator_factory)
+      geometry = RGeo::GeoJSON.encode(geojson)
+      geo_area.update_column(:geometry, geometry)
+    rescue RGeo::Error::InvalidGeometry
+      geo_area.destroy
+    end
+  end
+end
diff --git a/lib/tasks/deployment/20230215100231_normalize_geometries.rake b/lib/tasks/deployment/20230215100231_normalize_geometries.rake
new file mode 100644
index 000000000..275e37169
--- /dev/null
+++ b/lib/tasks/deployment/20230215100231_normalize_geometries.rake
@@ -0,0 +1,19 @@
+namespace :after_party do
+  desc 'Deployment task: normalize_geometries'
+  task normalize_geometries: :environment do
+    puts "Running deploy task 'normalize_geometries'"
+
+    progress = ProgressReport.new(GeoArea.count)
+    GeoArea.in_batches(of: 100) do |geo_areas|
+      ids = geo_areas.ids
+      Migrations::NormalizeGeoAreaJob.perform_later(ids)
+      progress.inc(ids.size)
+    end
+    progress.finish
+
+    # Update task as completed.  If you remove the line below, the task will
+    # run with every deploy (or every time you call after_party:run).
+    AfterParty::TaskRecord
+      .create version: AfterParty::TaskRecorder.new(__FILE__).timestamp
+  end
+end