Instead of looking for the website administrator, try searching whois for domain name registrant, and write them at the contact email address provided for the registrant. They can almost certainly “reach” the website administrator running on the domain they control.
Note that this does not mean that they will necessarily assist you with this, but it is worth a try. You might also recognize that you can’t really erase anything from the internet. There are just too many copies and caches around for that to work. Even if you do get the entry removed, it will live on!
As for DreamHost removing the data, that is not going to happen absent a court order or a valid DMCA takedown notice being received from a copyright holder - we don’t censor, or control, users’ content any more than the phone company interferes with what a telephone user says on the phone (it’s a freedom of speech thing).