Septic / OSSF
Most rural land in Marion County relies on a septic system
Outside city limits, most homes use an on-site sewage facility — a septic system — and Texas law requires a permit and a licensed site evaluation before you build or change one.
Most of Marion County has no public sewer. Homes outside city limits use a septic system. The official term is on-site sewage facility, or OSSF. Before you build a new system or change an old one, Texas law requires a permit. You also need a site evaluation by a licensed evaluator or engineer. They check your soil and lot to figure out which type of system fits.
The local government usually handles OSSF permits. Contact Marion County first to find out who issues permits in your area. If the county has not set up its own permitting office, the TCEQ regional office handles it. TCEQ is the Texas Commission on Environmental Quality — the state agency that oversees water and environmental rules. One exception: if your property is 10 acres or larger, a single-family home may qualify for a permit exemption. Even so, the system must meet all construction standards and must not pollute groundwater or cause a problem for neighbors. Plan to pump your septic tank every three to five years to keep it working right.
Source to confirm: TCEQ — OSSF Permits