2026 OSSF designated representative module 6 Comprehensive Questions and Answers | 100% Correct | A Grade

2026 OSSF designated representative
module 6 Comprehensive Questions and
Answers | 100% Correct | A Grade

Description
This OSSF Designated Representative (DR) exam (specifically related to Texas
Commission on Environmental Quality (TCEQ) course WWW305) evaluates a
candidate's ability to enforce OSSF rules, review permit applications, and conduct
site inspections.
This exam covers one of this six primary modules:
• Module 1: Introduction & Regulations. Covers the history of OSSF regulation
in Texas (starting in 1989), roles and responsibilities of DRs versus
installers/site evaluators, and the types of legal penalties (criminal, civil, and
administrative) for violations.
• Module 2: Basic OSSF Math. Focuses on calculations required for site
evaluation and system design, including trench width conversions, lot area in
acres, septic tank volume in gallons, and gravel requirements in cubic yards.
• Module 3: Wastewater & Public Health. Addresses pathogenic
microorganisms in domestic wastewater (bacteria, viruses, protozoa,
helminths) and the diseases they cause, such as typhoid, cholera, and
dysentery.
• Module 4: Permitting Process. Outlines the 9-step permitting process,
including site/soil evaluation, planning by a PE or RS, application review,
"Authorization to Construct" (ATC), and the final "Notice of Approval"
(NOA).
• Module 5: Site Evaluation & Soil. Detailed review of soil characteristics, site
suitability, and separation distances (e.g., the "Ten Acre Rule" for permit
exemptions).
• Module 6: System Design & Inspection. Focuses on the technical standards
for different systems like aerobic treatment units, low-pressure dosing, and
secondary treatment, alongside the DR’s duty to inspect these systems at
specific construction stages.




1

, Quiz_________________?
what systems can an Installer I install and repair -
Answer
-Standard absorptive drainfield
-ET (unlined) evapotranspiration drainfield
-Pumped effluent drainfield
-Leaching chamber drainfield
-Gravel-less pipe drainfield
-Soil substitution




Quiz_________________?
What materials are pipes from sewer stub to system -
Answer
cast iron
ductile iron
polyvinyl chloride (PVC)
Schedule 40




Quiz_________________?
What materials are pipes beneath driveways and sidewalks -

2

, Answer
Schedule 80 (PVC)
sleeved in schedule 40 PVC




Quiz_________________?
slope of house sewer -
Answer
no less than 1/8-inch fall per foot of slope




Quiz_________________?
Stub out -
Answer
highest possible elevation




Quiz_________________?
Where is a two-way cleanout located -
Answer
between the building and septic tank




3

, Quiz_________________?
additional cleanout location -
Answer
may be single type
upstream and within 5 ft of every 90-degree bend
every 100 feet




Quiz_________________?
What is the required design for septic tanks? -
Answer
Septic tanks must be of two- or three-compartment design.




Quiz_________________?
In a two-tank system, what should the first compartment contain? -
Answer
The first compartment must contain one-half to two-thirds of the
required volume.




Quiz_________________?
What is the purpose of having multiple compartments in a septic tank? -

4