Below you will find everything required in Sierra County to install a residential septic system and leach field.. For further information please contact The Environmental Health Department at (530) 993-6716 or via email.SC Building Permit Application BD-01Environmental Health Sewage Disposal ApplicationSC Authorization for Agent to Act on Property Owner's Behalf BD-02SC Plot Plan Requirements BD-05SC Water System Setback Certification BD-17SC Septic/Leach Field Permit Submittal Requirements BD-11