Remove cnd.notifications.help Pop-ups - Guide to Get Rid of 1-888-970-5911 Tech Scam

The past few days Google Chrome Virus pop-ups keep requiring me to force-quit Chrome! Each time I open a different tab, I get multiple VIRUS POP-UPS! The pop-ups even have audio voice recordings that state, "YOUR COMPUTER IS INFECTED WITH A VIRUS! CALL 1-888-970-5911. This happens on any computer I use, both Mac and Windows. I have scanned all the computers, they do not have viruses. I need to allow pop-ups to use this educational website, is there anything I can do to stop these pop-ups? PLEASE HELP!