Septic / OSSF
Rural properties in Freestone County usually need a septic permit
Most rural homes in Freestone County are not on a public sewer, so a permitted septic system is required before you can build or renovate.
Outside city limits in Freestone County, most homes use a septic system instead of a public sewer. The formal name is an on-site sewage facility, or OSSF. The county runs its own OSSF permit program. State rules from TCEQ (Texas Commission on Environmental Quality) set the base standards. You need a permit before you install, repair, expand, or replace a system. Skipping this step can cause problems when you sell and may leave you with no legal way to fix a failing system.
Freestone County handles the permits locally but must follow TCEQ rules. The county can also add its own requirements on top of the state rules. One exception worth knowing: TCEQ rules exempt a single-family home on 10 or more acres from the permit requirement if the system meets certain conditions — but you must still have a licensed site evaluation and keep all parts of the system at least 100 feet from the property line. Before you buy rural land or plan any building, ask the county about permits. The TCEQ website explains the statewide OSSF rules. The county's website has local permit program documents.
Source to confirm: TCEQ — Getting a Permit for an OSSF