These are fast disappearing. I like stumbling across old road signs. They can often point the way to interesting spots in rural areas. Some places I have run across on old road signs no longer show up on maps. I have been to Edberg and Ferrintosh, Alberta. I do not know what Nova is referring to. Nova is a common name for companies in Alberta so it could be anything from a place to a oil and gas operation. I would have explored further however it recently snowed. A bit of melting snow and ice leaves me to tackle this another day.
At one time the Alberta Motor Association had signs all over the province similar to this. Some of their signs pointed to old original townsites and old churches. The AMA signs have not been replaced or maintained in years and a number of them are falling by the wayside.