diff --git a/app/models/champs/carte_champ.rb b/app/models/champs/carte_champ.rb
index 3aa35bac9..d01f5e31b 100644
--- a/app/models/champs/carte_champ.rb
+++ b/app/models/champs/carte_champ.rb
@@ -76,7 +76,7 @@ class Champs::CarteChamp < Champ
       type: 'FeatureCollection',
       id: stable_id,
       bbox: bounding_box,
-      features: (legacy_selections_utilisateur + except_selections_utilisateur).map(&:to_feature)
+      features: geo_areas.map(&:to_feature)
     }
   end
 
@@ -84,23 +84,6 @@ class Champs::CarteChamp < Champ
     geo_areas.present?
   end
 
-  def selection_utilisateur_legacy_geometry
-    if selection_utilisateur_legacy?
-      selections_utilisateur.first.geometry
-    elsif selections_utilisateur.present?
-      {
-        type: 'MultiPolygon',
-        coordinates: selections_utilisateur.filter do |selection_utilisateur|
-          selection_utilisateur.geometry['type'] == 'Polygon'
-        end.map do |selection_utilisateur|
-          selection_utilisateur.geometry['coordinates']
-        end
-      }
-    else
-      nil
-    end
-  end
-
   def selection_utilisateur_legacy_geo_area
     geometry = selection_utilisateur_legacy_geometry
     if geometry.present?
@@ -131,35 +114,18 @@ class Champs::CarteChamp < Champ
 
   private
 
-  def selection_utilisateur_legacy?
-    if selections_utilisateur.size == 1
-      geometry = selections_utilisateur.first.geometry
-      return geometry && geometry['type'] == 'MultiPolygon'
-    end
-
-    false
-  end
-
-  def legacy_selections_utilisateur
-    if selection_utilisateur_legacy?
-      selections_utilisateur.first.geometry['coordinates'].map do |coordinates|
-        GeoArea.new(
-          geometry: {
-            type: 'Polygon',
-            coordinates: coordinates
-          },
-          properties: {},
-          source: GeoArea.sources.fetch(:selection_utilisateur)
-        )
-      end
+  def selection_utilisateur_legacy_geometry
+    if selections_utilisateur.present?
+      {
+        type: 'MultiPolygon',
+        coordinates: selections_utilisateur.filter do |selection_utilisateur|
+          selection_utilisateur.geometry['type'] == 'Polygon'
+        end.map do |selection_utilisateur|
+          selection_utilisateur.geometry['coordinates']
+        end
+      }
     else
-      selections_utilisateur
-    end
-  end
-
-  def except_selections_utilisateur
-    geo_areas.filter do |area|
-      area.source != GeoArea.sources.fetch(:selection_utilisateur)
+      nil
     end
   end
 end
diff --git a/lib/tasks/deployment/20200414104712_split_geo_area_selection_multipolygons.rake b/lib/tasks/deployment/20200414104712_split_geo_area_selection_multipolygons.rake
deleted file mode 100644
index 930a650aa..000000000
--- a/lib/tasks/deployment/20200414104712_split_geo_area_selection_multipolygons.rake
+++ /dev/null
@@ -1,18 +0,0 @@
-namespace :after_party do
-  desc 'Deployment task: split_geo_area_selection_multipolygons'
-  task split_geo_area_selection_multipolygons: :environment do
-    puts "Running deploy task 'split_geo_area_selection_multipolygons'"
-
-    Champs::CarteChamp.where.not(value: ['', '[]']).includes(:geo_areas).find_each do |champ|
-      if champ.send(:selection_utilisateur_legacy?)
-        legacy_selection_utilisateur = champ.selections_utilisateur.first
-        champ.send(:legacy_selections_utilisateur).each do |area|
-          champ.geo_areas << area
-        end
-        legacy_selection_utilisateur.destroy
-      end
-    end
-
-    AfterParty::TaskRecord.create version: '20200414104712'
-  end
-end
diff --git a/spec/factories/geo_area.rb b/spec/factories/geo_area.rb
index e46aa7bea..3f65aef6d 100644
--- a/spec/factories/geo_area.rb
+++ b/spec/factories/geo_area.rb
@@ -58,5 +58,27 @@ FactoryBot.define do
         }
       end
     end
+
+    trait :multi_polygon do
+      geometry do
+        {
+          "type": "MultiPolygon",
+          "coordinates": [
+            [
+              [
+                [2.428439855575562, 46.538476837725796],
+                [2.4284291267395024, 46.53842148758162],
+                [2.4282521009445195, 46.53841410755813],
+                [2.42824137210846, 46.53847314771794],
+                [2.428284287452698, 46.53847314771794],
+                [2.428364753723145, 46.538487907747864],
+                [2.4284291267395024, 46.538491597754714],
+                [2.428439855575562, 46.538476837725796]
+              ]
+            ]
+          ]
+        }
+      end
+    end
   end
 end
diff --git a/spec/serializers/champ_serializer_spec.rb b/spec/serializers/champ_serializer_spec.rb
index 54af2b224..1543bac2b 100644
--- a/spec/serializers/champ_serializer_spec.rb
+++ b/spec/serializers/champ_serializer_spec.rb
@@ -24,16 +24,9 @@ describe ChampSerializer do
     end
 
     context 'when type champ is carte' do
-      let(:champ) { create(:champ_carte, value: value, geo_areas: [geo_area].compact) }
-      let(:value) { nil }
-      let(:geo_area) { create(:geo_area, :cadastre, geometry: geo_json) }
-      let(:geo_json) do
-        {
-          "type" => 'MultiPolygon',
-          "coordinates" => coordinates
-        }
-      end
-      let(:coordinates) { [[[2.3859214782714844, 48.87442541960633], [2.3850631713867183, 48.87273183590832], [2.3809432983398438, 48.87081237174292], [2.3859214782714844, 48.87442541960633]]] }
+      let(:champ) { create(:champ_carte, geo_areas: [geo_area].compact) }
+      let(:geo_area) { create(:geo_area, :cadastre, :multi_polygon) }
+      let(:geo_json) { attributes_for(:geo_area, :multi_polygon)[:geometry].stringify_keys }
 
       let(:serialized_champ) {
         {
@@ -56,29 +49,7 @@ describe ChampSerializer do
       let(:serialized_value) { geo_json }
 
       context 'and geo_area is selection_utilisateur' do
-        let(:geo_area) { create(:geo_area, :selection_utilisateur, geometry: geo_json) }
-
-        context 'value is empty' do
-          let(:geo_area) { nil }
-
-          context 'when value is nil' do
-            let(:value) { nil }
-
-            it { expect(champ.selection_utilisateur_legacy_geo_area).to be_nil }
-          end
-
-          context 'when value is empty array' do
-            let(:value) { '[]' }
-
-            it { expect(champ.selection_utilisateur_legacy_geo_area).to be_nil }
-          end
-
-          context 'when value is blank' do
-            let(:value) { '' }
-
-            it { expect(champ.selection_utilisateur_legacy_geo_area).to be_nil }
-          end
-        end
+        let(:geo_area) { create(:geo_area, :selection_utilisateur, :polygon) }
 
         context 'old_api' do
           let(:serialized_libelle) { "user geometry" }
@@ -87,14 +58,6 @@ describe ChampSerializer do
           let(:serializable_object) { champ.selection_utilisateur_legacy_geo_area }
 
           context 'when value is coordinates' do
-            let(:value) { coordinates.to_json }
-
-            it { expect(subject).to eq(serialized_champ) }
-          end
-
-          context 'when value is geojson' do
-            let(:value) { geo_json.to_json }
-
             it { expect(subject).to eq(serialized_champ) }
           end
         end
@@ -120,33 +83,6 @@ describe ChampSerializer do
 
             it { expect(subject).to eq(serialized_champ) }
           end
-
-          context 'when value is geojson' do
-            let(:value) { geo_json.to_json }
-
-            it { expect(subject).to eq(serialized_champ) }
-          end
-
-          context 'when value is nil' do
-            let(:value) { nil }
-            let(:serialized_value) { nil }
-
-            it { expect(subject).to eq(serialized_champ) }
-          end
-
-          context 'when value is empty array' do
-            let(:value) { '[]' }
-            let(:serialized_value) { nil }
-
-            it { expect(subject).to eq(serialized_champ) }
-          end
-
-          context 'when value is blank' do
-            let(:value) { '' }
-            let(:serialized_value) { nil }
-
-            it { expect(subject).to eq(serialized_champ) }
-          end
         end
       end