diff --git a/app/controllers/announcement_feeds_controller.rb b/app/controllers/announcement_feeds_controller.rb
index b761d67..fa2b0d9 100644
--- a/app/controllers/announcement_feeds_controller.rb
+++ b/app/controllers/announcement_feeds_controller.rb
@@ -2,9 +2,6 @@ require "rss"
 class AnnouncementFeedsController < ApplicationController
 	include Admin::AnnouncementsHelper
 	def feed
-		Thread.new do
-			BulletinFeedCache.all_of({:invalid_date.ne=>nil,:invalid_date.lte => Time.now}).delete_all
-		end
 		uid = params[:uid]
 	    startdt = params[:start].blank? ? nil : params[:start]
 	    enddt = params[:end].blank? ? nil : params[:end]
diff --git a/app/models/bulletin_feed_cache.rb b/app/models/bulletin_feed_cache.rb
index 2982e2d..9147370 100644
--- a/app/models/bulletin_feed_cache.rb
+++ b/app/models/bulletin_feed_cache.rb
@@ -10,9 +10,14 @@ class BulletinFeedCache
   field :invalid_date, type: DateTime
   def self.regenerate_all
   	caches = self.all.to_a
-  	caches.each do |cache|
-  		cache.regenerate
-  	end
+    time_now = Time.now
+    caches.each do |cache|
+      if cache.invalid_date && cache.invalid_date <= time_now
+        cache.destroy
+      else
+        cache.regenerate
+      end
+    end
   	uids = BulletinFeed.all.pluck(:uid) - caches.collect(&:uid)
   	BulletinFeed.where(:uid.in=> uids).each do |feed|
   		feed.generate_one_cache()