Septic Systems
You Need a Permit for a Septic System in Comal County
Any new septic system — called an OSSF in Texas — requires a permit and an approved plan before construction can begin.
OSSF stands for On-Site Sewage Facility. That is the legal term for a septic system in Texas. You must get a permit and have an approved plan before you build, repair, or expand one. This applies to rural properties in unincorporated Comal County.
TCEQ sets statewide rules. The county or a local authority issues the actual permit. Check with TCEQ or Comal County to find out who the local permitting authority is for your address. Do not start construction before you have the permit — you can be required to dig it all up.
Source to confirm: TCEQ – Getting a Permit for an OSSF