On-Site Sewage Facilities (OSSF) are wastewater systems designed to treat and dispose of effluent on the same property that produces the wastewater. A septic tank and drainfield combination is the oldest and most common type of OSSF, although newer aerobic treatment units exist which represent scaled down versions of municipal sewage treatment plants. OSSFs account for approximately 25 percent of all domestic wastewater treatment in the United States. Tarrant County regulates the OSSF Inspection and Permit process for 23 cities and the unincorporated parts of the county. Follow this link for a list of Environmental Health Contract Cities.
In order to assure that wastewater is disposed safely, a permitting and inspection program requires that all OSSFs must be in substantial compliance with state regulations. Click here for a copy of the OSSF Rules and Regulations.
An OSSF permit is required for all new construction and anytime renovations significantly change the structure’s square footage or assigned water flow. Permits are also required if the type or strength of the wastewater changes from a residential wastewater classification. A repair/remodel permit is required anytime changes are made to an existing system. The regulations require that an owner must obtain a permit to repair, extended, modify or alter any of the disposal system’s existing components. The required OSSF permit application and resource documents are available for downloading at either the Residential Permit Application Packet or the Nonresidential Permit Application Packet.
It is very important to realize that nearly all of the unincorporated land in Tarrant County falls within the Extra Territorial Jurisdiction (ETJ) of existing cities. An ETJ is an area outside of a city’s limits where the city is allowed to require subdivision of acreage to meet minimum city requirements. Follow this link to the ETJ webpage for more information about these requirements.
There are several state requirements that must be met to properly subdivide acreage in the unincorporated areas of Tarrant County. State law requires that conditions be evaluated as to the suitability of the site if OSSFs are to be used. Follow this link to the Subdividing Land webpage for more information about these requirements.
Environmental Health staff has prepared a list of short answers for the most common OSSF inquires. Follow this link to the FAQ webpage for more information about the installation and maintenance of your OSSF.
County Telephone Operator 817-884-1111
Tarrant County provides the information contained in this web site as a public service. Every effort is made to ensure that information provided is correct. However, in any case where legal reliance on information contained in these pages is required, the official records of Tarrant County should be consulted. Tarrant County is not responsible for the content of, nor endorses any site which has a link from the Tarrant County web site.
100 E. Weatherford, Fort Worth, Texas 76196
Copyright 2001-2025 Tarrant County, TX