Septic Systems in Tarrant County Require a Permit

Tarrant County oversees septic systems (also called on-site sewage facilities, or OSSF) in areas without public sewer. This covers unincorporated areas and 23 cities. To put in a new septic system, you file an application, let the county check your site, and get a permit. Call the OSSF office for current permit fees.

A rule adopted in November 2025 says lots with a septic system must be at least one acre. That acre is measured after taking out drainage areas and floodplain land. Most unincorporated Tarrant County land also falls inside a city's planning zone. That means city rules may apply on top of county rules. Before you build or buy a lot without public sewer, call the county OSSF office at 817-212-7082.