Just ran across the Sacramento monitor's page from the EPA's RadNet Air Monitoring Data website; they say "To date, levels recorded at this monitor have been thousands of times below any conservative level of concern." (Mar. 22 press release here)
It's a bit curious, that before the Japan quake, the [beta gross count rate] readings were higher; perhaps spuriously & it wasn't fixed until the quake brought the monitor to attention. The "gamma gross count rate" graph below it shows no such pattern.