Texas On-Site Sewage Facilities (OSSF)
Regulations — Comprehensive Guide | State
Requirements & Compliance Overview |
Updated 2025
Aerobic digestion - ANSW✔️The bacterial decomposition and stabilization of sewage in the presence of
free oxygen.
Alter - ANSW✔️To change an on-site sewage facility resulting in: (A) an increase in the volume of
permitted flow; (B) a change in the nature of permitted influent; (C) a change from the planning
materials approved by the permitting authority; (D) a change in construction; or (E) an increase,
lengthening, or expansion of the treatment or disposal system.
Anaerobic digestion - ANSW✔️The bacterial decomposition and stabilization of sewage in the absence
of free oxygen.
Apprentice - ANSW✔️An individual who has been properly registered with the executive director
according to Chapter 30 of this title (relating to Occupational Licenses and Registrations), and is
undertaking a training program under the direct supervision of a licensed installer.
Authorization to construct - ANSW✔️Written permission from the permitting authority to construct an
on-site sewage facility showing the date the permission was granted. The authorization to construct is
the first part of the permit.
,Authorized agent - ANSW✔️A local governmental entity that has been delegated the authority by the
executive director to implement and enforce the rules adopted under Texas Health and Safety Code,
Chapter 366.
Borehole - ANSW✔️A drilled hole four feet or greater in depth and one to three feet in diameter.
Certified professional soil scientist - ANSW✔️An individual who has met the certification requirements
of the American Society of Agronomy to engage in the practice of soil science.
Cesspool - ANSW✔️A non-watertight, covered receptacle intended for the receipt and partial
treatment of sewage. This device is constructed such that its sidewalls and bottom are open-jointed to
allow the gradual discharge of liquids while retaining the solids for anaerobic decomposition.
Cluster system - ANSW✔️A sewage collection, treatment, and disposal system designed to serve two or
more sewage-generating units on separate legal tracts where the total combined flow from all units
does not exceed 5,000 gallons per day.
Commercial or institutional facility - ANSW✔️Any building that is not used as a single-family dwelling or
duplex.
Compensation - ANSW✔️A payment to construct, alter, repair, extend, maintain, or install an on-site
sewage facility.
Payment - ANSW✔️May be in the form of cash, check, charge, or other form of monetary exchange or
exchange of property or services for service rendered.
Composting toilet - ANSW✔️A self-contained treatment and disposal facility constructed to decompose
non-waterborne human wastes through bacterial action.
Condensate drain - ANSW✔️A pipe that is used for the disposal of water generated by air conditioners,
refrigeration equipment, or other equipment.
, Construct - ANSW✔️To engage in any activity related to the installation, alteration, extension, or repair
of an on-site sewage facility (OSSF), including all activities from disturbing the soils through connecting
the system to the building or property served by the OSSF. Activities relating to a site evaluation are not
considered construction.
Delegate - ANSW✔️The executive director's act of assigning authority to implement the on-site sewage
facility program under this chapter.
Designated representative - ANSW✔️An individual who holds a valid license issued by the executive
director according to Chapter 30 of this title (relating to Occupational Licenses and Registrations), and
who is designated by the authorized agent to review permit applications, site evaluations, or planning
materials, or conduct inspections on on-site sewage facilities.
Direct communication - ANSW✔️The demonstrated ability of an installer and the apprentice to
communicate immediately with each other in person, by telephone, or by radio.
Direct supervision - ANSW✔️The responsibility of an installer to oversee, direct, and approve all actions
of an apprentice relating to the construction of an on-site sewage facility, or the responsibility of a
maintenance provider to oversee, direct, and approve all actions of a maintenance technician relating to
the maintenance of an on-site sewage facility.
Discharge - ANSW✔️To deposit, conduct, drain, emit, throw, run, allow to seep, or otherwise release or
dispose of, or to allow, permit, or suffer any of these acts or omissions.
Edwards Aquifer - ANSW✔️That portion of an arcuate belt of porous, waterbearing predominantly
carbonate rocks (limestones) known as the Edwards (Balcones Fault Zone) Aquifer trending from west to
east to northeast in Kinney, Uvalde, Medina, Bexar, Comal, Hays, Travis, and Williamson Counties; and
composed of the Salmon Peak Limestone, McKnight Formation, West Nueces Formation, Devil's River
Limestone, Person Formation, Kainer Formation, Edwards Group, and Georgetown Formation, or as
amended under Chapter 213 of this title (relating to Edwards Aquifer). The permeable aquifer units
generally overlie the less-permeable Glen Rose Formation to the south, overlie the less-permeable
Comanche Peak and Walnut formations north of the Colorado River, and underlie the less-permeable
Del Rio Clay regionally.
Edwards Aquifer Recharge Zone - ANSW✔️That area where the stratigraphic units constituting the
Edwards Aquifer crop out, including the outcrops of other geologic formations in proximity to the
Regulations — Comprehensive Guide | State
Requirements & Compliance Overview |
Updated 2025
Aerobic digestion - ANSW✔️The bacterial decomposition and stabilization of sewage in the presence of
free oxygen.
Alter - ANSW✔️To change an on-site sewage facility resulting in: (A) an increase in the volume of
permitted flow; (B) a change in the nature of permitted influent; (C) a change from the planning
materials approved by the permitting authority; (D) a change in construction; or (E) an increase,
lengthening, or expansion of the treatment or disposal system.
Anaerobic digestion - ANSW✔️The bacterial decomposition and stabilization of sewage in the absence
of free oxygen.
Apprentice - ANSW✔️An individual who has been properly registered with the executive director
according to Chapter 30 of this title (relating to Occupational Licenses and Registrations), and is
undertaking a training program under the direct supervision of a licensed installer.
Authorization to construct - ANSW✔️Written permission from the permitting authority to construct an
on-site sewage facility showing the date the permission was granted. The authorization to construct is
the first part of the permit.
,Authorized agent - ANSW✔️A local governmental entity that has been delegated the authority by the
executive director to implement and enforce the rules adopted under Texas Health and Safety Code,
Chapter 366.
Borehole - ANSW✔️A drilled hole four feet or greater in depth and one to three feet in diameter.
Certified professional soil scientist - ANSW✔️An individual who has met the certification requirements
of the American Society of Agronomy to engage in the practice of soil science.
Cesspool - ANSW✔️A non-watertight, covered receptacle intended for the receipt and partial
treatment of sewage. This device is constructed such that its sidewalls and bottom are open-jointed to
allow the gradual discharge of liquids while retaining the solids for anaerobic decomposition.
Cluster system - ANSW✔️A sewage collection, treatment, and disposal system designed to serve two or
more sewage-generating units on separate legal tracts where the total combined flow from all units
does not exceed 5,000 gallons per day.
Commercial or institutional facility - ANSW✔️Any building that is not used as a single-family dwelling or
duplex.
Compensation - ANSW✔️A payment to construct, alter, repair, extend, maintain, or install an on-site
sewage facility.
Payment - ANSW✔️May be in the form of cash, check, charge, or other form of monetary exchange or
exchange of property or services for service rendered.
Composting toilet - ANSW✔️A self-contained treatment and disposal facility constructed to decompose
non-waterborne human wastes through bacterial action.
Condensate drain - ANSW✔️A pipe that is used for the disposal of water generated by air conditioners,
refrigeration equipment, or other equipment.
, Construct - ANSW✔️To engage in any activity related to the installation, alteration, extension, or repair
of an on-site sewage facility (OSSF), including all activities from disturbing the soils through connecting
the system to the building or property served by the OSSF. Activities relating to a site evaluation are not
considered construction.
Delegate - ANSW✔️The executive director's act of assigning authority to implement the on-site sewage
facility program under this chapter.
Designated representative - ANSW✔️An individual who holds a valid license issued by the executive
director according to Chapter 30 of this title (relating to Occupational Licenses and Registrations), and
who is designated by the authorized agent to review permit applications, site evaluations, or planning
materials, or conduct inspections on on-site sewage facilities.
Direct communication - ANSW✔️The demonstrated ability of an installer and the apprentice to
communicate immediately with each other in person, by telephone, or by radio.
Direct supervision - ANSW✔️The responsibility of an installer to oversee, direct, and approve all actions
of an apprentice relating to the construction of an on-site sewage facility, or the responsibility of a
maintenance provider to oversee, direct, and approve all actions of a maintenance technician relating to
the maintenance of an on-site sewage facility.
Discharge - ANSW✔️To deposit, conduct, drain, emit, throw, run, allow to seep, or otherwise release or
dispose of, or to allow, permit, or suffer any of these acts or omissions.
Edwards Aquifer - ANSW✔️That portion of an arcuate belt of porous, waterbearing predominantly
carbonate rocks (limestones) known as the Edwards (Balcones Fault Zone) Aquifer trending from west to
east to northeast in Kinney, Uvalde, Medina, Bexar, Comal, Hays, Travis, and Williamson Counties; and
composed of the Salmon Peak Limestone, McKnight Formation, West Nueces Formation, Devil's River
Limestone, Person Formation, Kainer Formation, Edwards Group, and Georgetown Formation, or as
amended under Chapter 213 of this title (relating to Edwards Aquifer). The permeable aquifer units
generally overlie the less-permeable Glen Rose Formation to the south, overlie the less-permeable
Comanche Peak and Walnut formations north of the Colorado River, and underlie the less-permeable
Del Rio Clay regionally.
Edwards Aquifer Recharge Zone - ANSW✔️That area where the stratigraphic units constituting the
Edwards Aquifer crop out, including the outcrops of other geologic formations in proximity to the
