To remove the alarm notifications, go to my account. In the section "Preferences for Alarms," uncheck the boxes in Step 1 to eliminate alarms for any containers added to to your dashboard in the future.
To remove alarms that have already been set on containers in your dashboard, select the Alarms tab on the left. In each category, select all of the containers for which you would like to remove alarms, click the bell icon at the bottom of the column, and uncheck the alarms you would like to remove. Click save and you're done.