It is from FAIRFAX ALERTS . A recorded notice of any current outages or county info deemed important to give out. I think I signed up for the alerts but didn't recognize the number. This had to do with a county building being reopened after it had been closed due to a power outage today.
I got a call from 15713501390 and who said it was with Fairfax Alerts (our county's emergency alert system) and said to call: 818-650-2131 and enter 21696911 to retrieve the message. I did NOT do that. None of those number I saw where associated with our County's alert system. I sent them an email to let them know. I'm guessing it's a scam.