If you view an individual waiver, on the top right hand corner there is an Archive Waiver button that you can click. This will remove the waiver from your waiver list.
Please note, that for posterity, we don't actually delete the submitted waiver, it's just archived elsewhere in case you should ever need it.
If you need to archive an entire batch of waivers within a certain date range, email us at support@webwaiver.com with the details.