CORRECT WELL DETAILED ANSWERS|LATEST
UPDATE!!!2025/2026|GUARANTEED
Disposal and treatment selection criteria - ANSWER✅✅Primary - OSSF must function
properly under specific soil and other conditions present of the site.
Secondary - Cost, Minimal maintenance, simplicity of operation, long-term reliability
Table XIII:
http://txrules.elaws.us/Gateway/Html//TITLE30/PART1/CHAPTER285/SUBCHAPTERI/285.91
/2018-11-29/HTML/30_0285_0091-21.html
Installer I is able to construct and repair these systems - ANSWER✅✅Standard Absorptive
drainfield
ET (unlined) evaporation drainfield
Pumped effluent drainfields
Gravelless pipe drainfield
Soil Substitution
*can install holding tank but is extremely rare
1
,See Table IX
http://txrules.elaws.us/Gateway/Html//TITLE30/PART1/CHAPTER285/SUBCHAPTERI/285.91
/2018-11-29/HTML/30_0285_0091-22.html
Piping in a house sewer - ANSWER✅✅Pipe is to be constructed of cast iron, ductile iron,
polyvinyl chloride (PVC) Schedule 40, standard dimension ratio (SDR) or other approved
material.
Pipes installed beneath driveways, sidewalks, or up to surface improvements must use sch.
80 PVC or sleeved sch. 40 PVC
Pipe from house to treatment unit must be as large as the building drain, but no smaller
than 3 inch diameter
Line must be watertight and a two-way cleanout plug must be provided between the
building and the septic system
Slope of house sewer - ANSWER✅✅No less than 1/8 inch fall per foot of pipe. The stub
out location shall be at the highest possible elevation
Cleanouts - ANSWER✅✅a two-way cleanout plug must be provided between the building
and the septic system.
Additional cleanout shall be provided upstream and within 5 feet of every 90 degree bend
and at least one cleanout every 100 feet
Septic tank - ANSWER✅✅Widely used on-site treatment option in Texas.
2
,Buried watertight tanks designed and constructed to receive wastewater from a home or a
business. They separate solids from liquids, provide limited anaerobic digestion of organic
matter, store solids, and allow the clarified liquid to discharge for further treatment and
disposal.
Settable solids and sludge settle at the bottom of the tank and accumulate. Scum and other
light material rise to the top
Performance of Septic Tanks - ANSWER✅✅Primary treatment, only partially treats
effluent and potential for disease transmission is virtually unchanged from raw wastewater
They should remove 60-70% of suspended solids and oil and grease present in raw
wastewater
At best only 30-40% of BOD is removed
Calculating size of tank - ANSWER✅✅must be a 2 or 3 compartment design with 2 or 3
tanks in a series or a single structure with multiple compartments.
-First compartment must contain 1/2 to 2/3 of the required volume for a 2 compartment
tank
-first compartment must contain 1/3 of required volume , but no less than 500 gallons
Tanks are sized to provide approximately 2-3 days detention time. The septic tank volume is
the liquid volume only.
Usefulness of the septic tank system decreases as the size of the establishment increases
3
, See Table II in 30 TAC 285.91
http://txrules.elaws.us/Gateway/codepdf//TITLE30/PART1/CHAPTER285/SUBCHAPTERI/285.
91/2018-11-29/PDF/201206290-2.pdf
Location of Septic Tank - ANSWER✅✅With respect to the home or building is usually
determined by the slope of the land and the bathroom and kitchen plumbing stub out from
the home.
In new construction establish the best location depending on the soil for the septic tank and
disposal field, then locate the house and the plumbing within
Table X shows minimum distances
Locate and attempt to avoid public water lines, if it cannot be avoided, follow rules to
minimize potential of contamination
Avoid high traffic areas as excessive loads could damage the areas. Locate tank near a route
where it is easily accessible for maintenance.
Also consider future home expansion and additions
Materials of a tank - ANSWER✅✅Sturdy, watertight construction,; appropriate materials
include:
-steel-reinforced, poured in place concrete
-steel-reinforced, pre-cast concrete
-fiberglass
-reinforced plastic polyethylene
4
UPDATE!!!2025/2026|GUARANTEED
Disposal and treatment selection criteria - ANSWER✅✅Primary - OSSF must function
properly under specific soil and other conditions present of the site.
Secondary - Cost, Minimal maintenance, simplicity of operation, long-term reliability
Table XIII:
http://txrules.elaws.us/Gateway/Html//TITLE30/PART1/CHAPTER285/SUBCHAPTERI/285.91
/2018-11-29/HTML/30_0285_0091-21.html
Installer I is able to construct and repair these systems - ANSWER✅✅Standard Absorptive
drainfield
ET (unlined) evaporation drainfield
Pumped effluent drainfields
Gravelless pipe drainfield
Soil Substitution
*can install holding tank but is extremely rare
1
,See Table IX
http://txrules.elaws.us/Gateway/Html//TITLE30/PART1/CHAPTER285/SUBCHAPTERI/285.91
/2018-11-29/HTML/30_0285_0091-22.html
Piping in a house sewer - ANSWER✅✅Pipe is to be constructed of cast iron, ductile iron,
polyvinyl chloride (PVC) Schedule 40, standard dimension ratio (SDR) or other approved
material.
Pipes installed beneath driveways, sidewalks, or up to surface improvements must use sch.
80 PVC or sleeved sch. 40 PVC
Pipe from house to treatment unit must be as large as the building drain, but no smaller
than 3 inch diameter
Line must be watertight and a two-way cleanout plug must be provided between the
building and the septic system
Slope of house sewer - ANSWER✅✅No less than 1/8 inch fall per foot of pipe. The stub
out location shall be at the highest possible elevation
Cleanouts - ANSWER✅✅a two-way cleanout plug must be provided between the building
and the septic system.
Additional cleanout shall be provided upstream and within 5 feet of every 90 degree bend
and at least one cleanout every 100 feet
Septic tank - ANSWER✅✅Widely used on-site treatment option in Texas.
2
,Buried watertight tanks designed and constructed to receive wastewater from a home or a
business. They separate solids from liquids, provide limited anaerobic digestion of organic
matter, store solids, and allow the clarified liquid to discharge for further treatment and
disposal.
Settable solids and sludge settle at the bottom of the tank and accumulate. Scum and other
light material rise to the top
Performance of Septic Tanks - ANSWER✅✅Primary treatment, only partially treats
effluent and potential for disease transmission is virtually unchanged from raw wastewater
They should remove 60-70% of suspended solids and oil and grease present in raw
wastewater
At best only 30-40% of BOD is removed
Calculating size of tank - ANSWER✅✅must be a 2 or 3 compartment design with 2 or 3
tanks in a series or a single structure with multiple compartments.
-First compartment must contain 1/2 to 2/3 of the required volume for a 2 compartment
tank
-first compartment must contain 1/3 of required volume , but no less than 500 gallons
Tanks are sized to provide approximately 2-3 days detention time. The septic tank volume is
the liquid volume only.
Usefulness of the septic tank system decreases as the size of the establishment increases
3
, See Table II in 30 TAC 285.91
http://txrules.elaws.us/Gateway/codepdf//TITLE30/PART1/CHAPTER285/SUBCHAPTERI/285.
91/2018-11-29/PDF/201206290-2.pdf
Location of Septic Tank - ANSWER✅✅With respect to the home or building is usually
determined by the slope of the land and the bathroom and kitchen plumbing stub out from
the home.
In new construction establish the best location depending on the soil for the septic tank and
disposal field, then locate the house and the plumbing within
Table X shows minimum distances
Locate and attempt to avoid public water lines, if it cannot be avoided, follow rules to
minimize potential of contamination
Avoid high traffic areas as excessive loads could damage the areas. Locate tank near a route
where it is easily accessible for maintenance.
Also consider future home expansion and additions
Materials of a tank - ANSWER✅✅Sturdy, watertight construction,; appropriate materials
include:
-steel-reinforced, poured in place concrete
-steel-reinforced, pre-cast concrete
-fiberglass
-reinforced plastic polyethylene
4
