I'm not sure this is certain proof of a Placerville Tesla Supercharger site, but I found pdf map on the El Dorado County Government website that shows two sites for Tesla Superchargers in El Dorado County. One site is in Placerville, in the Hangtown Village Square, which is right off highway 50, close to food and a few stores. This site appears to have been approved and a contract signed with Tesla. Although no construction has started yet that I can see.
The map also shows another location at Heavenly Ski Resort, which the map indicates they are still researching a location for the install. The map does not indicate when these were approved, but does indicated a targeted installation year though.
https://edcgov.us/uploadedFiles/Government/Air_Quality_Management/El%20Dorado%20County%20EV%20chargers%209-2014.pdf
The map also shows another location at Heavenly Ski Resort, which the map indicates they are still researching a location for the install. The map does not indicate when these were approved, but does indicated a targeted installation year though.
https://edcgov.us/uploadedFiles/Government/Air_Quality_Management/El%20Dorado%20County%20EV%20chargers%209-2014.pdf