Some dispatch centers are able to include GPS coordinates (latitude and longitude) in the call data that they send to Active911. Sometimes the accuracy of the coordinates are low (they come from estimates of the caller location) and should be discarded.
If the coordinates sent by dispatch or consistently accurate, you can direct Active911 to use these coordinates for mapping.
What to do
Login at active911.com and click on the Agency tab. Look for the option that reads Override mapping with GPS coords from your dispatch center? Change the option as desired. If the option is grayed out or disabled, you don't have the Edit Agency permissions - you will need to contact the admin of your agency account to have that permission added to your user account.
Warning: Change this setting with caution - it may break mapping!