diff --git a/da/stilt/obspack.py b/da/stilt/obspack.py
index 5f76a07703b9d6c10763f9806be557821f4c8fff..5f4ce7c57952b375d8c9e34700aead2b890355af 100755
--- a/da/stilt/obspack.py
+++ b/da/stilt/obspack.py
@@ -338,7 +338,7 @@ class ObsPackObservations(Observations):
 
 
 
-    def add_model_data_mismatch(self, filename):
+    def add_model_data_mismatch(self, filename, filename_cofilter):
         """
             Get the model-data mismatch values for this cycle.
 
@@ -405,6 +405,18 @@ class ObsPackObservations(Observations):
         #for obs in self.datalist:
         do_not_simulate=[]
         do_simulate=[]
+
+        eventids=[]
+        for line in open(filename_cofilter):
+            columns = line.split()
+            if columns[0] == "eventid":
+                pass
+            else:
+                eventids.append(columns[0])
+
+        eventids=array(eventids)
+        logging.info('eventids %s'%eventids)
+
         for i,obs in enumerate(self.datalist):
             obs.mdm = 1000.0  # default is very high model-data-mismatch, until explicitly set by script
             obs.flag = 99  # default is do-not-use , until explicitly set by script
@@ -414,6 +426,8 @@ class ObsPackObservations(Observations):
             identifier = obs.code
             species, site, method, lab, datasetnr = identifier.split('_')
 
+
+
             if site_info.has_key(identifier):
                 if site_foot.has_key(identifier):
                     path_foot  = site_foot[identifier]
@@ -422,6 +436,9 @@ class ObsPackObservations(Observations):
                     str_id = '%s'%obs.id
                     if any(str_id in s for s in files_foot):
                         logging.info("id in footprint %s" %str_id)
+                        if any(str_id in t for t in eventids):
+                            exclude_footprint = True
+                            logging.info("id in CO list, exclude this observation %s" %str_id)
                     else:
                         exclude_footprint = True
                         logging.info("id not in footprint %s" %str_id)